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This thesis presents a novel textile microwave interconnect that can be easily attached and removed from textile devices. Interconnects perform a vital role in carrying RF signals between an amplifier and an antenna or other devices. Conventional interconnects used for interconnecting non-flexible circuits perform this function with very low losses, however the same is not true for transmission lines made on fabrics using conductive threads or inks. This scenario of using interconnects on fabric systems is challenging. Due to the necessity of washing fabrics, permanent attachments on the fabric have disadvantages. Theconnectionpresentedinthisthesisisdonewithoutanymetalor rigid parts on the textile devices side. The connector is held in place by magnets which are shown to have no negative impact on the microwave connection. Two models are then explored, a microstrip connector and a grounded coplanar waveguide (CPW) connector. A detailed study of the models was done and it was found that both models have reasonable results up to2GHz. The interconnects are fully characterized by de-embedding the connection part. This can be used to predict the effect the interconnect will have when used to connect a microwave equipment. The microstrip version of the interconnect is attached to an antenna and the results presented. The interconnect has no negative effect on the reflection coefficient measurement of the antenna. Repeatability tests were also performed with this model, with no visible change in the connection quality between measurements. Different embroidery patterns and stitching designs were also investigated. These are used to reduce the amount of conductive thread used up to 59% reduction in thread ammount. A wearable antenna was fully converted from rigid copper sheet to a full textile design.

Cardiovascular disease is a prevalent group of conditions which affect a multitude of lives worldwide on a daily basis. For those individuals who require medical interventions for an occluded artery, stents are typically implanted to maintain vessel patency. Stents have developed with time from initial bare metal stents to recent drug eluting stents. The next generation of bioresorbable stents are undergoing continual research and development, particularly to battle the increased occurance of late stent thrombosis and in stent restenosis. The predominant aim of this PhD project is to assess the mechanical performance experimentally, in-vitro, of a well established, FDA approved scaffold, Absorb (Abbott Vascular, USA) composed of poly-L-lactic acid (PLLA), at a benchtop level. The work was also extended to assess the properties of novel polymers for vascular scaffold applications. Indentation, using atomic force microscopy (AFM) and a nanoindenter with a Berkovich tip, was the predominant means adopted to assess the properties of Absorb scaffold in virgin state. This was complemented with chemical analysis of the scaffold, including gel permeation chromatography (GPC) to assess the molecular weight and differential scanning calorimetry (DSC) for crystallinity measurements, to ascertain a conclusive perspective of the material in a virgin state. Additionally optical imaging and surface profilometry measurements were taken to reveal surface properties of the scaffold. To investigate the effect of in-vitro degradation, scaffold sections were subjected to benchtop in-vitro degradation, with properties assessed using the same methodology as for the virgin samples. The effect of accelerated degradation, together with the influence of nanoindenter tip geometry (pyramidal versus spherical), was evaluated on Absorb tubing samples. To review the feasibility of a novel co-polymer for scaffold applicaiton, the unique tubing material was comparatively assessed against Absorb, using the same testing parameters established on 4 Absorb. Finally, method of polymer synthesis and manufacture was evaluated using the same experimental technique; where both natural and synthetic polymers were tested, with results compared against those for stainless steel stents. It was discovered that AFM was possible to quantify the very local mechanical property, Young's modulus, of the scaffold. Nanoindentation provided a wide range of Young's modulus data for the virgin material, depending on the load level as well as additional factors such as ageing and the polymeric structure. For degradation, it was seen, with both AFM and nanoindentation, that there was no dramatic decline in the material stiffness over the two-year period; however a decline in the material was captured with chemical analyses (GPC and DSC). For accelerated degradation, it was possible to speed up the degradation process sufficiently at an elevated temperature; however, again, there was no definite observation of decline in Young's modulus even when the material reached a breakage state (i.e. extremely brittle). Instead, the material degradation was captured by the local stress-strain response obtained with spherical indentation, and further confirmed with chemical analyses. The novel co-polymer (PLA-PCL-PEG) did not perform adequately in comparison to Absorb, and hence requires further composition improvement. In contrast, the natural polymer (PHA) appeared to be a potential candidate for vascular scaffold application, with degradation behaviour subjected to further investigatations. In summary, it was seen that pyramidal indentation could not accurately capture the response of PLLA; spherical indentation can be used alternatively. The stress-strain response obtained with spherical indentaiton is able to capture the material weakening with degradation at a benchtop level, in both normal and accelerated conditions. For novel polymers, it is possible to assess their credibility as a scaffolding material at an early development stage, using the techniques and the benchmark data (i.e., FDA approved Absorb material) delivered in this thesis.

Bacterial cellulose (BC) with its high crystallinity, tensile strength, degree of polymerisation, and water holding capacity (98%) becomes increasingly attractive as 3D nanofibrillar material for biomedical applications. Such multi-scale fibrillary BC networks can be potentially functionalised with electrically conductive moieties to facilitate the conductive properties required for various smart biomedical devices, in particular, in the construction of bioelectronic neural interfaces. In this thesis, BC fibres are chemically modified with poly(4-vinylaniline) (PVAN) interlayer for further enhancement of electrical conductivity and cell viability of subsequent polyaniline (PANI) coatings as a bilayer grafted BC nanocomposite. This functional poly(4-vinylaniline)/polyaniline (PVAN/PANI) bilayer can be efficiently anchored onto BC fibrils through successive surface-initiated atom transfer radical polymerisation and in situ chemical oxidative polymerisation. PVAN is found to have promoted the formation of a uniform PANI layer with 1D nanofiber- and nanorod-like supramolecular structures, with an overall augmentation of PANI yield, hence further improved electrical performance. Compositional and microstructural analysis reveals such a PVAN/PANI bilayer with a thickness up to ~2 µm on BC formed through a significant growth of PANI with rough surface morphology due to the insertion of PVAN, which has improved the functional properties of the BC nanocomposites. Successful impregnation of both layers onto BC fibrils was corroborated with systematic microstructural and chemical analysis. The solid-state electrical conductivity of such synthesised BC nanocomposites with PVAN interlayer reaches as high as (4.5±2.8)×10-2 S.cm-1 subject to the amounts of PVAN chemically embraced. Electrochemical examination evinces the switching in the electrochemical behaviour of BC/PVAN/PANI nanocomposites at -0.70/0.74 V (at 100 mV.s-1 scan rate) due to the existence of PANI, where the maximal electrical performance can be achieved at charge transfer resistance of as low as 21 Ω and capacitance of as high as 39 μF. Both electrochemical and mechanical properties can be tailored onto an incomplete BC dehydration, where a mathematical model is herein developed to predict BC water loss accordingly. BC/PVAN/PANI nanocomposites are thermally stable up to 200 ºC. Furthermore, further improvement of the electrical conductivity has been achieved through grafting Carbon Nano Tubes (CNTs) into the BC/PVAN/PANI nanocomposites, where the interactions between PANI and CNTs present new electrochemical characteristics with enhanced capacity. PANI/CNTs coatings with a nanorod-like morphology can promote the efficient ions diffusion and charge transfer, resulting in the increased electrical conductivity up to (1.0±0.3)×10-1 S.cm-1. An escalating amplification of the double charge capacity to ~54 mF of the CNTs grafted BC nanocomposites was also detected through electrochemical analysis. In addition, the thermal stability of CNTs grafted BC/PVAN/PANI nanocomposites are improved, and they become stable up to 234 ºC. Cytocompatibility tests conducted using two neuronal cell linages show non-cytotoxic effects for PC-12 Adh cells and SVZ neural stem cells, confirming cell viability that can be over 80 % and neuronal differentiation capability of the electrically functionalised BC-based nanocomposite membranes, which can induce neurites outgrowth up to 115±24 μm long. These voltage-sensible nanocomposites can hence interact with neural cells, thereby significantly stimulate specialised response. These findings pave the path to the new tissue engineered neural interfaces which embraces electronic functions into the tissue regeneration, to enable full functional neural tissue recovery.

Experimental analysis of Ultrasonically Assisted Turning (UAT) for metallic alloys with the aim of producing a set of empirical formulas to predict the value of cutting forces as well as chip compression ratios, is of great impact to any future research related to metal cutting field. Such empirical formula could also predict the value of surface roughness and machining accuracy for produced parts under both conventional cutting (CT), and UAT domains. While UAT has been around for many years, no much improvement has been done to enhance UAT system for force reduction as well as system stability application. The reason behind this is the lack of information regarding the quantifying of underlaying mechanisms in UAT. In recent years, with the advancement of better control systems as well as enhanced UAT systems, a new unique system was improved and constructed at Loughborough University (LU) for better understanding of UAT performance for hard alloys. Yet this system was not tested with conventional materials. Those materials represent engineering materials used day-to-day in almost all manufacturing plants. Stainless steel, cast iron, aluminium, brass, and bronze were chosen to represent various categories of ferrous and nonferrous metals. Materials used in this study represent a variety of traditional engineering materials. They include both ferrous and nonferrous; stainless steel (SS), cast iron (CI), aluminium (Al), brass (Br) and bronze (Bro). The objective was to present the behaviour of UAT vs. CT with well-established materials to try to broaden the knowledge of UAT. As forces are reduced, the proposed mechanisms include an interconnected effect of several mechanisms - hardening and softening ones. Hardening mechanisms are a term used to describe the interaction of the tool and workpiece under UAT, which results in workpiece material being hardened. Softening mechanisms are a term used to describe the interaction of the tool and workpiece under UAT, which results in workpiece material being softened. So, by introducing well-established materials for the UAT study, models could be enhanced more easily to be able to quantify both the hardening and softening mechanisms. In this thesis, it introduces the development of model to predict cutting forces, chip compression ratio, surface roughness, and machining accuracy for produced surfaces using both UAT and CT. Experimental research has resulted in new contributions to knowledge in the following ways: (1) one-dimensional UAT is more advantageous when it comes to machining common engineering materials, (2) development of a model to predict process parameters under both UAT and CT, (3) Demonstrate the behaviour of force reduction and surface roughness improvement for a number of materials under UAT. Up to the time of writing this thesis no such model exists, and the motivation to develop such model - to fill a knowledge gap in this area - is to better quantify the one-dimensional UAT improvements as a machining method.

In recent years, huge advances have been made in the development of photovoltaic (PV) technology. Anti-reflective (AR) and anti-soiling (AS) coatings have demonstrably improved the energy output of PV modules and are establishing commercial viability. However, the durability of such coatings has not been sufficiently addressed and remains a key concern. In this thesis, a range of testing methods have been identified and evaluated for the purpose of assessing the performance, durability, environmental stability and wear resistance of AR and AS hydrophobic coatings. A comprehensive set of performance parameters and characterisation tools were identified to assess the degradation mechanisms of several coating formulations. Comparative results were generated for coatings before and after being subjected to a range of stress tests. New test rigs and procedures, including a sand impact and raindrop simulation test, were also designed and implemented to provide further insight into the degradation of coating performance following exposure to sand and rain water. The durability of two types of single layer (ARC1 and ARC2) and a multilayer anti-reflective (MAR) coatings were investigated. The reflectance obtained from single layer AR coatings after damp heat and abrasion tests suggest poor durability and inadequate useful lifetime despite an initial performance increase in transmittance when applied to PV cover glass. The test results on the MAR coating, designed and produced in CREST, showed excellent durability against all environmental and mechanical stresses. Six variants of a hydrophobic coating, ASC1 were stress tested during the development of an anti-soiling coating for PV cover glass application. The degradation mechanisms of each variant were used to improve the performance and durability of the coating. In addition, the ASC2 hydrophobic coating, that is commercially available for application on PV cover glass, was durability tested under same stresses as ASC1 coating for comparison. The ASC2 coating showed good resistance to mechanical stress and UV exposure. However, damp heat testing of the ASC2 coating lead to a significant performance drop revealing that it is not durable in high temperature and humidity conditions. The results indicate that better performance could be achieved if these types of coatings are designed and developed for specific climatic conditions. Three hydrophobic coatings commercially available for other applications such as on ophthalmic lenses and smart phone displays, ASC3, ASC4 and ASC5 coatings were subjected to a range of stress tests to demonstrate suitability for use in PV applications. The hydrophobic properties of ASC3 and ASC5 coatings showed good durability against mechanical abrasion, but both failed to perform well against exposure to UV light. There was no visual or performance degradation observed after both abrasion resistance and sand impact test on both ASC3 and ASC5 coatings. Scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis of ASC5 showed that the nanoparticles responsible for the hydrophobic properties of the coating degraded under UV light with the loss of fluorine. Nevertheless, the ASC5 coating showed excellent stability against damp heat and thermal cycling stress. Furthermore, the ASC4 coating showed good durability against temperature cycling and UV light exposure. The coating also retained its hydrophobicity after 1000 hours of damp heat exposure. In addition, the coating showed a variable abrasion resistance against different abrasive materials. The test results suggest that ASC4 coating has good adhesion to the glass substrate with good durability against cheesecloth and felt pad abrasion. However, a harder scour pad damaged the surface of ASC4 severely. The test results suggest that all three hydrophobic coatings (ASC3, ASC4 and ASC5) have their strengths and weaknesses to withstand certain environmental and mechanical stresses due to their design for different applications. The durability of these coatings against UV light and abrasion resistance would need to be improved if they are to be applied to PV cover glass.

Alzheimer's disease (AD) is the most common type of dementia (>70% of the cases). Although it was discovered more than one century ago, the existing treatments for AD only produce a modest amelioration of the symptoms and there is still no available cure. AD not only causes severe distress to the patients and caregivers, but it is also associated with a large economic burden to society, since after the age of 65, the risk of developing AD doubles every five years, and by the age 85 the prevalence increases to 50%. This large and global impact is inherently associated with current major challenges in AD, which include the lack of effective treatments, preventive strategies and reliable biomarkers for early diagnosis.

The use of 3D Vision is becoming increasingly common in a range of industrial applications including part identification, reverse engineering, quality control and inspection. To facilitate this increased usage, especially in autonomous applications such as free-form assembly and robotic metrology, the capability to deploy a sensor to the optimum pose for a measurement task is essential to reduce cycle times and increase measurement quality. Doing so requires knowledge of the 3D sensor capabilities on a material specific basis, as the optical properties of a surface, object shape, pose and even the measurement itself have severe implications for the data quality. This need is not reflected in the current state of sensor haracterisation standards which commonly utilise optically compliant artefacts and therefore can not inform the user of a 3D sensor the realistic expected performance on non-ideal objects. This thesis presents a method of scoring candidate viewpoints for their ability to perform geometric measurements on an object of arbitrary surface finish. This is achieved by first defining a technology independent, empirical sensor characterisation method which implements a novel variant of the commonly used point density point cloud quality metric, which is normalised to isolate the effect of surface finish on sensor performance, as well as the more conventional assessment of point standard deviation. The characterisation method generates a set of performance maps for a sensor per material which are a function of distance and surface orientation. A sensor simulation incorporates these performance maps to estimate the statistical properties of a point cloud on objects with arbitrary shape and surface finish, providing the sensor has been characterised on the material in question. A framework for scoring measurement specific candidate viewpoints is presented in the context of the geometric inspection of four artefacts with different surface finish but identical geometry. Views are scored on their ability to perform each measurement based on a novel view score metric, which incorporates the expected point density, noise and occlusion of measurement dependent model features. The simulation is able to score the views reliably on all four surface finishes tested, which range from ideal matt white to highly polished aluminium. In 93% of measurements, a set of optimal or nearly optimal views is correctly selected.

In 2014, there were 850,000 people living with dementia in the UK, creating an economic burden of £26.3 billion a year. 62% of dementia patients are diagnosed with Alzheimer's Disease (AD). AD is a slow progressing disease with three phases: a long prodromal stage followed by mild cognitive impairment and then late AD. The prodromal phase of AD is on average 30 years. So, when the first symptoms become apparent, the pathology in the brain is extensive. If Alzheimer's could be diagnosed early, when the pathological load is lower, this may improve the chances of finding a disease modifying therapy. For diagnosis during the prodromal stage to be viable, patients would need to be diagnosed through mass screening, with the most appropriate diagnosis method being biomarker detection in peripheral blood. There are an increasing number of articles in literature researching the use of non coding RNA sequences called microRNA (miRNA) as biomarkers for AD. However, their viability in diagnosing prodromal AD is unknown and the current miRNA detection method, the polymerase chain reaction (PCR), is time consuming, expensive and requires experienced personnel, making it unsuitable for use in mass screening. Therefore, the aim of the thesis was to investigate miRNA as a prodromal biomarker with a new detection method to determine the usability of miRNA as a prodromal AD biomarker. AD is characterised by the build up of amyloid β and hyper phosphorylated tau in the brain. The movement of tau through the brain is divided into 6 Braak stages. Chapter 4 aimed to determine the point at which miRNAs deregulate in AD. To achieve this, post mortem brain tissue was obtained through all 6 Braak stages. The RNA from the post-mortem brain samples were isolated and the change in miRNA levels were determined using PCR and the ΔΔct method. After comparing miRNA to a spike in control the 4 miRNAs tested showed no significant change in miRNA levels through the progression of AD. One of the first signs of AD is the activation of astrocytes in the brain. The aim of Chapter 5 was to determine the effect of the deregulated miRNAs on astrocytes. An astrocytoma cell line was activated using lipopolysaccharides and TNF α then transfected so specific miRNA were over expressed. The concentration of metabolites, cytokines and growth factors were measured in the cell supernatant. Results showed mir 210 regulated G CSF and mir 223 regulated glutamate consumption. Finally, the feasibility of rapid detection of miRNA was investigated using a quartz crystal microblance (QCM). The QCM, assembled within a custom built microfluidic flow cell, was driven at its fundamental resonance frequency. Shifts in the third Fourier harmonic current and the resonance frequency were measured for a range of concentrations of a single stranded DNA (ssDNA). The results show feasibility for rapid quantitative detection of ssDNA to 60 ng/mL, in an easy to use label free assay. Amplification of the signal was seen with the addition of electrochemical potential and the use of particles. Results looking at the deregulation of miRNA in the temporal cortex showed no significant change, therefore further work is needed looking at alternative miRNA sequences. The results with ssDNA suggest that quartz crystal resonator has the potential for rapid, specific and quantitative miRNA detection. However, amplification strategies would help to achieve the clinically relevant limit of detection in peripheral blood.

Since its commercial introduction, Negative Pressure Wound Therapy (NPWT) has become a widely accepted option for managing and treating non-healing wounds. Despite the success of NPWT, its mechanisms of action remain unclear. This has several explanations such as, NPWT is a generic multi-modal technology that can deliver a broad range of treatment goals depending on the patient being treated and these goals can be achieved by altering a range of variables which all add to the complexity of studying the therapy. In addition, variations in treatment regimens, depending on wound type, size and location, make it very difficult to standardise across health care settings and to optimise wound healing outcomes. Moreover, recent findings collectively imply that understanding of the biomechanical environment, such as mechanical stress and oxygen tension on wound bed, is fundamental for further mechanistic investigations of wound healing when NPWT applied. Although current scientific findings from clinical studies can show a facet of its aetiology, there is lack of enabling tools bridging these outcomes with the clinical management strategies of wounds. Hence, our understanding on the biomechanical aspects of the wound tissue during NPWT is rather limited. Computational modelling has demonstrated its advantages for investigating biomechanical effectiveness of medical devices where clinically relevant complexities can be introduced in each increment and the range of variables can be alternated simultaneously. Hence, the main aim of this thesis is the application of advanced computational modelling as enabling tools to gain insights of the mechanical effects of NPWT on tissues with particular focus on deformation and tissue oxygenation in wound tissue. A finite element (FE) modelling procedure was introduced to predict the mechanical behaviour of different types of wound and its reliability was validated against experimental measurements. The experimental model showed a good comparison with FE model predictions. Then, multi-cohort of parameters, including wound characteristics, its location and surrounding tissue structures, were evaluated. The wound characteristics study showed the effectiveness of NPWT on wound deformation. FE models were further used in this capacity to evaluate the effects of surrounding tissue structure based on wound location and its characteristics. A full-scale anatomical model was necessary to show full effect of NPWT response phenomena exhibited. The main reason is that in simplified model the magnitudes of displacements and stresses were underestimated when the total surrounding tissue volume relative to the wound volume was not fully implemented. Following that, a multi-scale model to predict the tissue oxygenation changes around the wound cavity subject to NPWT application was developed with varying the wound surface area. Finally, the effect of complex anatomical geometry on tissue oxygenation changes was modelled and the clinical applicability of the established framework for tissue oxygenation changes was demonstrated. FE models based on multi-parametric studies were compared with currently available literature data to demonstrate its predictive capabilities. The results of this study made valuable contributions to our existing understanding of the mechanics of wound tissue during the NPWT process. Outcomes from the current study allowing stratified NPWT in terms of quantify the level of tissue deformations at specific location in the wounded area with varied pressure levels. With further verification using clinical data as inputs, the developed computational models would aid the stratification of personalised wound management using NPWT for complex wounds.

Carbon Fibre Reinforced Polymers (CFRPs) have proven to be a popular choice in many applications given their higher desired and advantageous high strength to weight ratio, which makes them ideal for extreme loading conditions such as; low velocity impacts through airborne debris (1-100 m/s), high velocity impacts with fragmenting hailstone clouds, or even close-proximity air blast shock waves. In a real environment, these dynamic loading conditions are very rarely mutually exclusive, and so it is necessary to analyse the combined loading of both an impact and air blast shockwave which then creates the following question. Which is the most destructive, an impact closely followed by an air blast or visa-versa? With this in mind, the presented research is first focused on the experiment testing of a consistent CFRP specimen material to ballistic rigid steel and fragmenting ice projectiles, as well as air blast shock wave loading with in-situ deformation analysis via digital image correlation from high speed photography alongside the post loading damage analysis via x-ray tomography. The second part of the research then focuses on the development of a meso-scale modelling strategy for carbon fibre reinforce polymer (CFRP) via a phenomenological continuum damage approach, which delivers accurate through-thickness stress responses, strain-rate sensitive behaviour, and full damage-initiation and evolution tracking of various damage modes with stiffness degradation. The modelling approach was incorporated into Abaqus Explicit 6.14-4 as a user defined subroutine (VUMAT), with inter-ply delamination modelled via cohesive zone surfaces (CZSs). Following a new approach to obtaining and extrapolating material parameters for CFRPs utilising a comparative literature search to obtain an array of common ratios, the CFRP model was validated against the ballistic and air blast experiments, the results of which demonstrate the model delivering accurate correlation of both the specimens deformation behaviour and observed resultant damage to the various experimental loading conditions without modification of the modelling parameters. Finally, the modelling approach was then employed to predict and analyse the hypothetical scenarios of the impact closely followed by an air blast and visa-versa, subjecting the CFRP to set combined loading conditions within the limits of those set out within the scope of the experiment studies.

Robotic grippers have been constantly improving over the years to become more dextrous and adaptable in handing difficult objects with variations in their shape or uncertainty in their positioning. A challenge that remains difficult until now is the ability to handle delicate objects that can be easily considered as defective due to their interaction with the gripper, such as the case for food products or finely machined parts. An interesting emerging approach to tackle this challenge is to rethink the origin of the problem, which is the fact that all conventional grippers are made of hard and rigid components that can easily damage objects during grasping if not precisely controlled based on reliable sensory feedback. Hence, creating gripper fingers from soft materials makes them inherently safe and relaxes the need for sophisticated sensing and complex control. However, several open research challenges exist that are hindering the full utilisation of soft robotic components. In the context of soft grippers, relying primarily on the soft nature of the fingers to passively and gently adapt to its targets although highly desirable, consequently means that no sensory feedback is available to have better control over the grasping process or confirm its success. In this research, a low-cost soft gripper was developed based on the ribbed pneumatic bending actuators with embedded bend sensing, in order to investigate the potential for sensor-guided control of soft gripper fingers. A purely data-driven approach is proposed that utilises basic sensory feedback to accurately estimate and control the bending of individual soft gripper fingers using simple empirical models that do not require any material characterisation or precise physical models. First, an experiment was designed to study the effect of varying the internal channel dimensions of soft finger samples with the same outer size, on their bending and force responses at variable input pressures. The results of this experiment provided useful design guidelines that can be followed to maximise the bending and force capabilities of the soft fingers and identified the best performing design of those tested. The experiment also illustrated how the soft finger's behaviour is governed by its designed morphology, which is consistent for fixed input conditions. The second step was to embed the soft fingers with resistive flex sensors, which change in resistance during bending without hindering the desired compliance. Additionally, onboard pressure sensors were used to measure the actual internal pressure developed inside the finger during actuation. Linear regression and artificial neural networks (ANN) are two common data-driven techniques that were implemented in this research. Both were fed with training data consisting of the flex and pressure measurements acquired by testing a soft finger sample at different pressure levels and orientations, with the corresponding synchronised bending angle measured using a vision system. The developed models were successfully validated using new data acquired at untrained conditions, with the ANN providing more accurate bending estimations at the expense of heavier computation. Lastly, a PID controller was developed which utilises the simple empirical model to estimate the current bending angle, calculates the error from a target value, and outputs a duty cycle value for the PWM signal regulating the supplied pressure. The controller was successful in controlling the modelled sensorised soft finger to accurately follow stepped and sinusoidal reference signals. Moreover, the combined multi-sensory feedback from the complete soft gripper was analysed to investigate the possibility of distinguishing between the free-bending and contact states, as well as differentiating between objects of different sizes. The main interest here was to evaluate if useful inferences can be made using the raw data from the flex and pressure sensors without having to model the real bending response of each soft finger individually. An experiment was conducted which involved grasping a set of objects of variable sizes and weights and collecting the resulting sensory feedback. The results of the experiment provided a clear relationship between the grasped object size and the averaged final flex sensor readings from opposing fingers supplied with the same pressure input. The results also showed the possibility of achieving contact detection by simply monitoring the current flex sensor's response during grasping and comparing it to the known free-bending response. A clear deviation can be witnessed at the occurrence of contact depending on the object size, which can be then used to stop the actuation. Furthermore, an interesting observation from this experiment was witnessed when monitoring the flex sensor's response during grasping against the measured internal pressure. Two distinct response curves were identified which reflects whether the object was grasped at the fingertips (precision) or encapsulated within the gripper (power), providing additional useful feedback about the grasp using simple sensory feedback. The last contribution of this research was the investigation of additive manufacturing as an alternative fabrication method to the manual multi-stage soft lithography technique. Automating the fabrication of soft grippers is not only desired for its speed and ease of use, but more importantly to improve the output consistency so that an empirical model derived for a specific actuator design can be potentially used for different samples with minimal need for updating. Functional soft finger based on the pleated morphology and flexible strain sensors were successfully 3D printed using a standard material extrusion-based printer after tuning the print parameters. The bending and force responses of the unit were experimentally characterised, and fatigue tests conducted to evaluate consistency. The printed soft finger was able to operate at higher pressures and hence generated larger contact forces while maintaining the desired compliance. Combining two of those units results in a two-fingered soft gripper that can be easily customised and directly printed in a single stage. The proposed data-driven modelling approach was successfully implemented using the printed finger as an additional validation to demonstrate the flexibility of using this approach with different actuator morphologies and materials. The outcomes of this investigation provided design guidelines and print settings recommended to successfully print air-tight soft fingers and highly flexible strain sensors. Finally, the results of this research deliver a simple purely data-driven approach for modelling and controlling soft grippers that are not limited to a specific morphology or material, as well as an automated process for fabricating those with better consistency. The key requirement is to generate relatively small datasets from simple, inexpensive sensors during the systematic experimental testing, as demonstrated in this research with the moulded and 3D printed soft gripper fingers. Ultimately, with innovations in additive manufacturing technologies enabling more difficult geometries and wider choices of flexible materials to be printed, combined with advanced machine learning algorithms processing larger grasping datasets, more dextrous sensorised soft grippers can be reliably printed to safely manipulate delicate targets in various real-life applications.

Over the past century tennis balls have seen little development, despite issues with durability and recyclability. Over the same period rackets have seen several development iterations through the use of wood, aluminium and carbon fibre reinforced composites frames. Players physical capabilities have dramatically improved and even line-calling has been automated. In professional tennis, balls are used for as little as nine games before being discarded, whilst recreational players demand a long-lasting product at minimal cost. Balls are comprised of a vulcanised rubber core, which is pressurised, and woven felt covering. Similarities in materials, combined with strict performance limits defined by the International Tennis Federation (ITF) and consumer pressures culminates in a product with low profit margins and little market differentiation. The work presented in this thesis focussed on the elastomeric material used to manufacture the core of tennis balls, presenting a scientific means of assessing alternative ball core materials that could benefit players and brands alike. Ball tracking data collected during professional tournaments, spanning the major court surfaces used in professional tennis, was analysed and used to determine the impact frequency and conditions a ball is subjected to during play. The range of impact conditions determined were replicated in the laboratory and subjected to digital image correlation techniques (GOM Correlate Professional), which were applied to measure the surface strains and strain rates present during impact. The results of which enabled the transformation of typical ball impact conditions in professional tennis into mechanical testing conditions representative of what occurs during impact. Current pressurised and pressureless ball core rubber were subjected to tensile testing, matching as closely as was possible, the strains and strain rates measured during impact. Dynamic mechanical analysis (DMA) was also utilised to characterise the viscoelastic properties of current ball core rubber. The characterisation of current materials provided a benchmark against which alternatives could be compared and enabled the implementation finite element (FE) simulations of ball cores during impact. FE modelling utilised advanced viscoplasticity material models (Bergstrӧm-Boyce model) enabling the viscoelastic and strain rate dependent behaviour of rubber to be incorporated, eradicating the need to artificially tune model coefficients, as seen in previous examples of tennis ball modelling. Having quantified the conditions required for materials characterisation testing and developed a methodology for the simulation of pressurised ball core impacts, alternative materials were identified and assessed. Thermoplastic elastomers (TPEs) were identified as materials with potential for replacing vulcanised rubber. TPEs offered potential improvements to pressure retention properties, recyclability as well as the opportunity to utilise thermoplastic manufacturing processes. When subject to the same materials characterisation testing and FE modelling as ball core materials, TPEs exhibited, in part, comparable properties to ball core rubber, with simulations estimating similar ball core performance for melt processible rubber TPE. The work presented in this thesis implies TPE materials are worthy of further investigation for use as tennis ball cores.

The rise in market-approved cellular therapies demands for advancements in process analytical technology (PAT) capable of fulfilling the requirements of this new industry. Unlike conventional biopharmaceuticals, cell-based therapies (CBT) are complex 'live' products, with a high degree of inherent biological variability. This exacerbates the need for in-process monitoring and control of critical product attributes, in order to guarantee safety, efficacious and continuous supply of this CBT. There are therefore mutual industrial and regulatory motivations for high throughput, non-invasive and non-destructive sensors, amenable to integration in an enclosed automated cell culture system. While a plethora of analytical methods is available for direct characterization of cellular parameters, only a few satisfy the requirements for online quality monitoring of industrial-scale bioprocesses. In the last twenty years, quartz crystal resonators (QCR) have demonstrated a high degree of versatility and applicability across different biomedical applications, capable of acting as both gravimetric and force balances. The strain induced by micron-sized particles attached onto the oscillating quartz causes significant deviations inthe magnitude of any odd Fourier harmonic responses, as a function of the oscillation frequency and amplitude. This transduction principle, named Anharmonic Acoustic Detection Technique (ADT), could potentially complement traditional quartz resonators in the study of cell-surface interactions. The initial part of the experimental work covered in this thesis investigates the interactions between model micron-sized particle with surface-immobilized proteins and the QCR. In a coupled oscillator system, the relative amount/density of molecular complexes formed between the particle and the resonator modifies the nonlinear acoustic response measured by the third Fourier harmonic of the current. A second part extends the investigation towards characterization of membrane antigen expression of cord-blood derived CD34⁺ erythroprogenitors, differentiated down the erythroid lineage. The final contribution of this work demonstrates the feasibility of implementing QCR sensors as online quality monitoring tools for surface marker profiling and characterization of cell mechanical properties, features also appropriate for applications in point-of-care clinical diagnostics.

In this thesis, the use of time-modulated arrays are considered for two dimensional direction finding systems. The work has a particular aim of providing a low cost solution with small computational overhead. A solution is provided for the one-dimensional case before it is extended to work in two dimensions, whilst new techniques are considered for the control of the array. The work focuses on utilising the simultaneously generated sidebands caused by switching the elements of the array to obtain a direction estimate and this is achieved using the power spectrum of the array's output. The use of real-valued arithmetic delivers the low-computational requirement, whilst the use of switches to implement time-modulation delivers the low cost requirement. Methods for the control and manipulation of these simultaneous beams are also given, as are the considerations needed for implementing such an array. These techniques are derived theoretically using array equations but confirmed experimentally by utilising a novel, fully featured simulation of a time-modulated planar array with customisable properties.

Photovoltaic (PV) solar cells provide a simple and smart way for direct conversion of sunlight into electricity, which is a clean alternative to conventional fossil fuel-based energy conversion methods. As a result of ongoing research, photovoltaic technologies are becoming both more efficient and cheaper. Thin film solar cells, particularly chalcogenides, are a promising area of research as they offer substantial cost savings as a consequence of reduced material usage and cheaper atmospheric fabrication processes. Cu(In,Ga)(S,Se)2(CIGS)solar cells are currently the best performing commercially deployed thin film PV technology. However the best performing CIGS devices are fabricated using sophisticated vacuum-based co-evaporation or co-sputtering systems requiring high capital costs and high energy budgets. Lower costs are achievable using alternative atmospheric deposition methods. These typically involve two step processes consisting of electrodeposition, nanoparticle or molecular solution coatings followed by high temperature annealing in a chalcogen containing atmosphere.

Asymmetric and symmetric cylinder drives are the major actuators for hydraulic linear motion control applications. The asymmetric type is the most popular one and can be found in various areas, industrial, civil and even aerospace. Its compact design in structure and high power to weight ratio are highlighted, but nonlinear behaviours are found in these applications. An asymmetric cylinder is usually controlled by a symmetric ported control valve, which introduces difficulty in the motion control of the cylinder. To avoid such issue, symmetric cylinder drives are typically chosen for high-performance dynamic response applications. This thesis focusses at improving the modelling and driving of the asymmetric cylinder drive system. The major nonlinearities in asymmetric cylinder systems occur when the control valve crosses its null position, causing pressure jumps, and system parameters switching to new values. In this scenario, the system is usually operating at low speed, in which the friction influence is an important factor. In addition, energy efficiency is always a concern in hydraulic applications, a valve-controlled asymmetric cylinder drive can have better controllability than a pump-controlled system, but its energy efficiency is worse than the latter. The aims of this research are to: • Improve modelling of asymmetric cylinder drive systems. • Improve the driving of asymmetric cylinder systems at low speed and velocity reversal with friction consideration. • Combine the advantages of a valve-controlled and a pump-controlled asymmetric cylinder drive system for energy efficiency purpose. A detailed analysis of a valve-controlled asymmetric cylinder system is carried out, and the nonlinearities behaviours are investigated in structure and theory aspects. The simulation modelling in this thesis reveals the system performances when the control valve travels across its null position, and this process is simulated with a numerical solution. An analytical solution is developed, showing that the new analytical solution runs 200 times faster than the original numerical method in simulation. Friction is inevitable in any device and it plays an important role in hydraulic nonlinearities, especially when the system runs at low speed and velocity reversal. Existing friction models are investigated and reviewed, but limited friction models considered the pressure influence in hydraulics. A new friction model for hydraulic system is developed on current LuGre model. This new friction model includes pressure term, acceleration term and velocity term. The new friction model is validated by experimental results and improvements are demonstrated. Under the consideration of energy efficiency, functionality, cost and feasibilities, a hybrid pump-controlled asymmetric cylinder system that combines the merits of a valve-controlled system and a pump-controlled system is implemented. Its pros and cons are investigated and analysed. Its simulation model is built to aid further analysis of the existing nonlinearities. Comparing the simulation results of the hybrid pump-controlled asymmetric cylinder system with the valve-controlled asymmetric cylinder system, the energy efficiency of the hybrid pump-controlled system is 20% better and can be further optimised. The various experimental results validate the simulation model of the hybrid system. Therefore, the functionality and feasibility of the energy efficient design of the hybrid pump-controlled system are validated. The design circuit of the hybrid pump-controlled asymmetric cylinder system is not fully optimised, and improvements can be achieved in future works including replacing the pilot shifted four-way valve with a solenoid valve, adding accumulators to stabilise the pressure in the service line and adding a controller to optimise the system performance.

Blind Audio Source Separation (BASS), inspired by the "cocktail-party problem", has been a leading research application for blind source separation (BSS). This thesis concerns the enhancement of frequency domain convolutive blind source separation (FDCBSS) techniques for audio separation in highly reverberant room environments. Independent component analysis (ICA) is a higher order statistics (HOS) approach commonly used in the BSS framework. When applied to audio FDCBSS, ICA based methods suffer from the permutation problem across the frequency bins of each source. Independent vector analysis (IVA) is an FD-BSS algorithm that theoretically solves the permutation problem by using a multivariate source prior, where the sources are considered to be random vectors. The algorithm allows independence between multivariate source signals, and retains dependency between the source signals within each source vector. The source prior adopted to model the nonlinear dependency structure within the source vectors is crucial to the separation performance of the IVA algorithm. The focus of this thesis is on improving the separation performance of the IVA algorithm in the application of BASS. An alternative multivariate Student's t distribution is proposed as the source prior for the batch IVA algorithm. A Student's t probability density function can better model certain frequency domain speech signals due to its tail dependency property. Then, the nonlinear score function, for the IVA, is derived from the proposed source prior. A novel energy driven mixed super Gaussian and Student's t source prior is proposed for the IVA and FastIVA algorithms. The Student's t distribution, in the mixed source prior, can model the high amplitude data points whereas the super Gaussian distribution can model the lower amplitude information in the speech signals. The ratio of both distributions can be adjusted according to the energy of the observed mixtures to adapt for different types of speech signals. A particular multivariate generalized Gaussian distribution is adopted as the source prior for the online IVA algorithm. The nonlinear score function derived from this proposed source prior contains fourth order relationships between different frequency bins, which provides a more informative and stronger dependency structure and thereby improves the separation performance. An adaptive learning scheme is developed to improve the performance of the online IVA algorithm. The scheme adjusts the learning rate as a function of proximity to the target solutions. The scheme is also accompanied with a novel switched source prior technique taking the best performance properties of the super Gaussian source prior and the generalized Gaussian source prior as the algorithm converges. The methods and techniques, proposed in this thesis, are evaluated with real speech source signals in different simulated and real reverberant acoustic environments. A variety of measures are used within the evaluation criteria of the various algorithms. The experimental results demonstrate improved performance of the proposed methods and their robustness in a wide range of situations.

The demand for rapid in vitro diagnosis (IVD) point-of-care testing (POCT) systems to be used outside of a traditional healthcare setting has been vastly expanding. Effective fabrication solutions need to be forward thought to satisfy miniaturized and heterogeneously integrated POCT. A holistic engineering approach to increase sensitivity of a miniaturised fluorescence detector for POCT systems was carried out. The study investigated how effective fabrication methods could deliver a better performance fluorescence detector (FD) to be well fitted in sophisticated and varying POCT systems. SLA and SLS were introduced in the study and evaluated through the measurement of surface texture of roughness with an Alicona Infinite Focus instrument. SLA was ultimately selected to produce a functional OFD through the validation with a selected fluorescence dye, i.e., Cy5. A limit of detection was reached of 1.209x10-10 Mol to reach a certain level of IVD detection. In addition to this anisotropic wet etching was investigated as a portal into the development of miniaturised integration microfluidic FD. A case study was performed to compare the sensitivity of the FD's design, manufactured and tested against another style of FD. The work creates an avenue of rapid screening POCT OFD fabrication solutions with a view on high performance and multi-functional detection systems not only in POCT, but also high-throughput (HTP) screening in life sciences and environmental applications.

While modern-day healthcare continues to improve in terms of available treatments and life expectancy in many countries, increasing costs of providing medical services to aging populations place these systems under increasingly severe pressure. With continuing increases in chronic afflictions and ailments related to old age, more cost-efficient and long-term solutions are needed to meet these challenges. Regenerative medicine offers the potential for more effective long-term treatments, but is hindered by the high cost of the desired treatments in terms of development and implementation, owing to the complexity of the living materials used for such therapies. The work described in this thesis focuses on improving the level of control over the local cellular environment in order to reduce the need for costly materials (especially growth factors). Both surface topology and immobilization of growth factors have previously been shown to have an impact, and this research investigates potential interaction between these aspects. Patterning and immobilization of bio-active compounds are combined for the culture of human mesenchymal stem cells on surfaces with differently scaled patterns and concentrations of immobilized TGF-β1. Initial work focused on the creation of patterned surfaces with feature sizes ranging from 1 to 50 µm. Patterns were successfully produced in Poly (Ethylene Glycol), Polystyrene and Polycaprolactone surfaces using a microparticle-based moulding process. Further work resulted in the successful immobilization of TGF-β1 onto chemically modified surfaces, chiefly Polycaprolactone. Proteins were successfully immobilized onto Polycaprolactone surfaces at concentrations up to 4 pmol/cm2, with exact concentrations dependent on the parameters of the immobilization process. Finally, the developed methods were combined in a hybrid experiment using both patterned surfaces and growth factor immobilization. Results demonstrated a probable link between surface patterning and the effectiveness of immobilized growth factors, although further work is needed to more accurately describe any underlying processes.

Carbon-fibre-reinforced polymer/titanium stack components possess outstanding mechanical properties such as excellent strength-to-weight ratio, high corrosion resistance, stiffness, low density and excellent fatigue properties. These mechanical advantages translate to better fuel efficiency and energy saving. These hybrid materials are not only popular but also a substitute for metals in many structural applications. Recently, a novel machining technique - ultrasonically assisted drilling (UAD) - was introduced to machine hard-to-cut materials, in which vibrations with a low amplitude, low energy and high frequency was superimposed on the drilling tool in the axial direction during the conventional drilling process. This hybrid machining technique brings along several advantages, including multi-fold reduction in forces, required to drill in difficult-to-cut materials such as glass, ceramics, CFRP or hard alloys, hence improving machinability, associated with high-quality surface finish, and meeting standards required for modern materials. Finally, a novel control system is designed and manufactured for UAD machining technique, capable of switching between vibratory parameters for each material constituent in the CFRP/Ti stack was implemented. The development of the control system in UAD resulted in a significant reduction in the average drilling forces, both in the composite and metal phase - 33% - 88%. The developed process appeared to improve drilling in the CFRP/Ti stack, with enhanced surface quality observed, reducing (or, in some cases, eliminating) damages induced during the drilling process in comparison to CD, with a two-to-three-fold reduction in the surface roughness.

National health organisations and authorities have reported an increment in death cases due to cancer. To overcome this issue and improve the survival rate, it is needed to find new clinical methods, early diagnoses techniques and treatments. Radiation and chemotherapy have been used for years to treat cancer. However, these types of treatments have serious side effects such as hair loosing, the mortality of healthy cells and other organs. A new treatment based on prodrugs therapy is in development with the intention to reduce these side effects or to replace the harmful treatments completely. Prodrug treatments need an activation agent, i.e. a catalyst, to convert the prodrug delivered to the cancerous cells to an active drug in-situ. Metals such as palladium can be used as a catalyst to activate the prodrug in targeted cancer cells. In this PhD study, the research was divided into two major aspects. The first aspect was to design and manufacture a catalyst carrier with specific properties and specifications such as biocompatibility of the materials used as the carrier, suitable mechanical properties to withstand physiological loads and conditions, and cost efficiency of the production. Two different manufacturing methods were used, Powder Metallurgy technique and Arc Melting technique, to achieve the optimal fabrication method. The carriers were characterised via XRD, SEM, EDS, DSC methods and mechanical tests to ensure the carrier meets the requirements. In the second stage, the carriers were coated with Palladium in its metallic state (i.e. Pd0). The coating was required to meet the requirements of being unalloyed, pure and free of any contamination, and its deposition cost and time effective. Four coating methods were employed. Powder Metallurgy technique and sintering (with and without space holder), Magnetron Sputtering, Pulsed Laser Deposition and Supersonic Beam Cluster Deposition methods were used to apply Palladium coating onto the carriers. The coating was characterised by XPS, XRD, FIB, XRF, SEM, EDS, biochemical and in-situ biological tests. The results obtained confirmed that the devices achieve high biocompatibility of the materials, and an excellent superelasticity can withstand the loads inside the human body. Also, the Magnetron sputtering methods as a coating method demonstrated it is the most effective for achieving a uniform and long-lasting deposited layer. The devices were able to activate a clinically approved prodrug.

Adaptation is a complex feature of living tissues, including bone. Compared with engineering materials, the structural and material properties of bone keep changing to fulfil the requirements of physiological functions throughout a lifetime. However, a disorder of this process could lead to serious bone diseases such as osteoporosis. Understanding the adaptation associated with architecture and mechanical properties of trabecular bone are key factors in diagnosis, prediction and treatment of osteoporosis. There are well-established theories that mechanical loads such as exercise can stimulate structural adaptation of trabecular bone. Previous research focused mostly on the effect of in-vivo loading on trabecular microstructure at the whole-bone level in both animal or human studies, while understanding of mechanically-induced local adaptation of human trabecular bone is rather limited. The study was based on a hypothesis that trabecular-bone adaptation, including microstructural and mechanical competence, is inherently heterogeneous, hence, may not be captured adequately by the global analysis based on averaging.

This thesis presents a novel method for monitoring the healing of severe bone fractures. This would be particularly useful during the first two to four weeks after trauma where x-ray and computerised tomography scanning cannot provide an accurate indication regarding the healing status of the fractured bone. The technique involves measuring the radiofrequency transmission from one bone-implanted monopole to another, each one located on either side of the bone fracture. Throughout this thesis, it is envisaged that the monopoles will also act as the screws of an external fixation implanted into patients for the stabilization and alignment of the bone fragments. To replicate a simplified version of a human limb, several multi-material semi-solid phantoms were developed to represent bone marrow, bone cortical, blood and muscle. Medical literature indicates that the amount of blood found at the initial stage of a bone fracture decreases as bone regeneration takes place towards the healed state. The rate of change of the S₂₁ of the implanted monopoles over time was shown to provide a tool that allowed the estimation of the amount of blood (hematoma) inside any bone fracture. In this thesis it has been shown that as the effective dielectric properties of the investigated fractured area shifted from the dielectric properties of blood towards the properties of bone, the S₂₁ of the monopoles increased, thus, this technique can be used to indicate bone healing. The simulated results were validated in measurements using several multi-material phantoms and a real lamb joint. Finally, an analytical model on the approximation of the S₂₁ of the monopoles in the near field inside the multi-material phantoms was developed. The results showed good agreement over the frequency spectrum of 1 to 4GHz and reasonable agreement over the parametric investigation of separation distance between them for the range of 1 to 7cm. This will potentially allow the application of the proposed technique for special types of fractures where the screws of the external fixation are separated by different distances.

Even with the rapid technological advancements, robots are still not the most comfortable machines to work with. Firstly, due to the separation of the robot and human workspace which imposes an additional financial burden. Secondly, due to the significant re-programming cost in case of changing products, especially in Small and Medium-sized Enterprises (SMEs). Therefore, there is a significant need to reduce the programming efforts required to enable robots to perform various tasks while sharing the same space with a human operator. Hence, the robot must be equipped with a cognitive and perceptual capabilities that facilitate human-robot interaction. Humans use their various senses to perform tasks such as vision, smell and taste. One sense that plays a significant role in human activity is 'touch' or 'force'. For example, holding a cup of tea, or making fine adjustments while inserting a key requires haptic information to achieve the task successfully. In all these examples, force and torque data are crucial for the successful completion of the activity. Also, this information implicitly conveys data about contact force, object stiffness, and many others. Hence, a deep understanding of the execution of such events can bridge the gap between humans and robots. This thesis is being directed to equip an industrial robot with the ability to deal with force perceptions and then learn force-based tasks using Learning from Demonstration (LfD). To learn force-based tasks using LfD, it is essential to extract task-relevant features from the force information. Then, knowledge must be extracted and encoded form the task-relevant features. Hence, the captured skills can be reproduced in a new scenario. In this thesis, these elements of LfD were achieved using different approaches based on the demonstrated task. In this thesis, four robotics problems were addressed using LfD framework. The first challenge was to filter out robots' internal forces (irrelevant signals) using data-driven approach. The second robotics challenge was the recognition of the Contact State (CS) during assembly tasks. To tackle this challenge, a symbolic based approach was proposed, in which a force/torque signals; during demonstrated assembly, the task was encoded as a sequence of symbols. The third challenge was to learn a human-robot co-manipulation task based on LfD. In this case, an ensemble machine learning approach was proposed to capture such a skill. The last challenge in this thesis, was to learn an assembly task by demonstration with the presents of parts geometrical variation. Hence, a new learning approach based on Artificial Potential Field (APF) to learn a Peg-in-Hole (PiH) assembly task which includes no-contact and contact phases. To sum up, this thesis focuses on the use of data-driven approaches to learning force based task in an industrial context. Hence, different machine learning approaches were implemented, developed and evaluated in different scenarios. Then, the performance of these approaches was compared with mathematical modelling based approaches.

This research aims at developing a fundamental understanding of the deformationmechanisms in single crystal 6H silicon carbide (6H-SiC). Owing to the continuous miniaturization of electronics devices, silicon carbide (SiC) continues to be of exceptional interest to the electronic industries. It is poised to replace silicon-based MEMS devices used in the most technically demanding environment due to its excellent bandgap characteristics, extreme hardness, high thermal conductivity, chemical inertness and wear resistivity. On the other hand, SiC can also be used as structural components in the aerospace, automotive and nuclear industries where components are subjected to high temperature, high power frequency or irradiated environments. Components from SiC can range from component dimensions as small as 0.1µm to the largest in the macroscopic scale with dimensions in centimetres. A good understanding of deformation behaviour is, therefore, crucial for reliable component design across scales. Understanding the deformation mechanisms could also help to inspire new insight in designing novel components with controlled mechanical properties. In this thesis, the plastic deformation in single crystal 6H-SiC was investigated. Nanoindentation tests with a Berkovich indenter were conducted on different crystallographic orientations. The experimental data obtained was used to calibrate a three-dimensional finite element model with an explicit time integration scheme incorporating a suitably modified crystal plasticity theory. The comparison of load-displacement curves as well as surface topography analysis to experiments have shown that the modelling approach can reasonably elucidate the underlying principles of deformation in this Hexagonal Close Packed like material. The predictions from the simulations indicated that the activation of slip system is rather complicated with activation of the pyramidal family being significant, which differentiated from general beliefs that basal slip is the only dominant slip system when considering plastic deformation in this material. Following this, a nanoscratching experiment was conducted along four different crystallographic orientations. Results showed that although there is not much difference in macroscopic response such as cutting forces, the elastic-plastic transitions and microcrack formation are different. The experimental results from the scratching experiment further strengthen the claims that the slip system activation is complicated and all of the slip systems should be taken into account instead of just considering basal slip when considering plastic deformation in this material. Finally, an enhanced numerical model was developed to account for this deformation behaviour. The modelling framework has the predictive capability of determining machining forces, induced damage and residual stress in the machined component. Such an approach may be used in the component fabrication industry to mitigate the detrimental effects of machining during manufacture.

Technology assimilation is an increasingly important topic in modern manufacturing industries. Successful technology assimilation not only supports the development of better products, but also can provide a competitive edge in fast-moving markets, such as the automotive industry. Technology assimilation is a complex process, with a high failure rate, with technologies that seem promising in the research phase, failing to be assimilated into the final product. This high failure rate for technology assimilation is costly, in both time and other resources, and so has resulted in the effect of the Valley of Death . Tools and methods for technology assessment are essential enablers of successful product development, a process that requires collaboration from both engineering and business professionals to be successful. This thesis presents research that was aimed at ameliorating the Valley of Death effect during technology assimilation, particularly in the environment of the automotive Original Equipment Manufacturers (OEMs). The research was undertaken in close collaboration with Jaguar Land Rover Limited. Such collaboration provided first-hand information and direct engagement that supported and enabled this research. A review of the relevant theoretical concepts and the process of technology assimilation was undertaken, with a focus on the tools and methods that have been applied. The literature review resulted in an identification of the gaps and challenges among current technology assimilation approaches. This work also resulted in a conceptual model being developed to represent three different viewpoints that it is argued are essential to understand for successful technology assimilation, namely: Natural Technological Viewpoint, Social Technological Viewpoint and Human Technological Viewpoint. These three viewpoints were then further elaborated in a Hexahedron Model of Technology, alongside consideration of technology assimilation complexity, capability of technology and the contribution of a potential technology, allowing six different perspectives to be considered during the process of assessing if a specific technology is suitable for assimilation into a complex product. In this thesis, the Hexahedron Model of Technology, as the name suggests, allows consideration of six different facets for successful technology assimilation, and can be further elaborated to include more aspects of technology based on the future work. This model can also support an enterprise to understand how to develop the technology in a direction that might increase the likelihood of successful assimilation. The approach to technology assimilation presented in the thesis first sets out a Technology Assessment Framework and methods for populating and applying it. The Hexahedron Model of Technology provides a structural platform for assessing the subjective factors that need to be considered during technology assimilation in a structured way. This process helps to reduce the number of technologies that are considered for assimilation; by pre-eliminating some relatively weak technologies and taking forward only those more likely to succeed. A Technology Refinement and Modification Algorithm was then developed that provides suggestions, at a high-level, for the direction for technology improvement to help make the technology better match the requirements. This algorithm hence helps to further increase the chances of successful technology assimilation. The Technology Assessment Framework and Technology Refinement and Modification Algorithm were applied to two case studies. One of these cases was conducted to demonstrate the process of the proposed approach whereas the other one was part of a real-world project in collaboration with the Jaguar Land Rover Limited. Overall, this research demonstrates a two-step holistic approach to technology assimilation that first reduces the number of technologies considered for assimilation and then establishes the direction for development of new technology to improve the likelihood of successful technology assimilation.

The design and manufacture of optimised structural components is desired by many areas of engineering. These components could be optimised for structural performance, weight reduction, or combinations of attributes. Lightweight porous materials offer opportunities to produce such components with designed internal structures of controlled porosity as their mechanical performance is controlled by their porosity and density. Such components can be designed, through methods such as topology optimisation to offer improved mechanical properties when compared to homogeneous counterparts. Yet the production of such heterogeneous materials or components is presently beyond the capabilities of current manufacturing technologies. The manufacture of large-scale heterogeneous porous materials, that could realise the optimised designs of topology optimisation cannot currently be manufactured in high-volumes. In this thesis a method is proposed to modify the localised porous structure of thermosetting polymer foams using ultrasound, as a future method to control the localised porosity of a bulk component.

Infectious diseases are currently one of the greatest global challenges in medicine. Rapid and precise diagnosis and identification of pathogen is important for timely initiation of appropriate antimicrobial therapy. However, many patients with infectious diseases receive empirical treatment rather than appropriate pathogen-directed therapy. As a result antimicrobials have been overused and/or misused, which has ultimately led to antimicrobial resistance (AMR). AMR is broadly considered as the most significant public health threat facing the world today. Policy makers from all over the world have recognised the urgent need for rapid point-of-care (POC) diagnostics that would not only identify pathogens but also provide antimicrobial susceptibility profiles in meaningful timeframe to initiate appropriate antimicrobial therapy and thereby prevent AMR. Traditional culture-dependent diagnostic methods are still considered as gold standard methods. But they are very slow and generally require 18 to 48 hours with further 8 to 48 hours to perform antibiotic susceptibility test. Among culture-independent methods, PCR and ELISA are label-based, costly, laborious and require specialised equipment and trained personnel to operate them. Lateral flow assays (LFAs) that are low-cost, simple, rapid and paper-based portable detection platforms are very popular as they can be applied at the POC. However, it is difficult to integrate them with electronics and they also suffer from higher false-positive rates than PCR and ELISA. Optical, electrochemical and acoustic biosensor-based methods allow label-free, whole-cell bacterial detection. Among them, a relatively new technique called Anharmonic acoustic Detection Technique (ADT) is integrable and can be applied at the POC for rapid, label-free, low-cost, detection. ADT also allows detection with high specificity, which is lacking in most of the other methods; therefore, it was selected to explore its use for whole-cell bacterial detection. For the first time, ADT was integrated with specific multivalent DNA aptamers that bind whole bacterial cell for direct detection and quantification of viable E. coli (KCTC 2571) bacteria. This aptamer-based assay coupled with ADT constituted the anharmonic acoustic aptasensor. DNA aptamers were immobilised through biotin and streptavidin conjugation, onto the gold surface of quartz crystal resonator (QCR) to capture the target bacteria and the detection was accomplished by measuring the shift in the maximum value of magnitude of the transduced 3fsignal (3 times the drive frequency) i.e. ΔI3fmax upon binding, when driven at fundamental resonance frequency. This aptasensor provides a practical method for rapid, sensitive and quantitative on-site detection of bacteria confidently up to 2.5 x 10⁴ (corresponding to 10⁶ E.coli/mL) in 5 min, as compared to standard frequency shift (Δf₀)and dissipation shift (ΔD) measurements. Anharmonic acoustic aptasensor also demonstrated specificity by distinguishing between specific (E.coli) and non-specific (S.typhi) interactions. Linear quantitative correlation could be reliably achieved with 3fsignal (R²= 0.984) for four concentrations of E.coli bacteria (10⁵-10⁸ cells/mL), than with Δf₀ and ΔD. Comparative performance of other bio-receptors of different size (anti-E.coli antibody) and different length (shorter linker with thiolated aptamer) was assessed against longer linker with biotinylated aptamer which gave the highest sensitivity and specificity than these two different receptors. To further enhance the sensitivity and specificity of this system, the same E.coli-binding aptamers were modified by introducing smart chemical moieties into their structure such that the newly configured aptamer sequences not only quantitatively detected bacteria but also gave characteristic signal, highly specific for that interaction. Thus, this anharmonic acoustic aptasensor can be applied for rapid, sensitive, specific and quantitative detection of whole-cell bacteria and thereby, can reduce diagnostic cycle and improve the appropriate prescribing of antimicrobial therapy and thus can be used to combat AMR.

The powder bed fusion additive manufacturing process category consists of a group of key-enabling technologies. These technologies allow the fabrication of both intrinsic and complex structures for a series of applications, including astronautics. The pull factor that influenced this investigation was to explore the potential application of laser-based additive manufacturing (also known as 3D printing), for the manufacture of engineering assets and componentry, using the available extra-terrestrial natural resources as feedstock. The successful realisation of this manufacturing approach in an extra-terrestrial environment could enable a sustainable presence in space by providing the ability to build assets and tools needed for building and maintaining life-sustaining habitats on the Moon, to support future extra-terrestrial human activity.

Atmospheric-pressure plasma systems are a fast-emerging field of engineering research as they obviate the requirement of the costly and bulky vacuum systems required by low pressure plasmas. A wide range of applications such as medical treatments, surface sterilisation and aerodynamic flow control have recently been emerging in the literature, presenting exciting opportunities for new plasma devices or treatment methods to be brought to the forefront. These plasmas offer an alternative to existing applications such as cleaning or chemical production as they hold the advantage that they do not require any other chemicals such as bleach, the only input to the system being power and air. Plasmas can be utilised in so many applications because of the clever design of the devices that create them, most applications require a new design configuration in order to optimise the plasma for each case. As with many fields, developments are required in the efficiency, cost, efficacy and size of said plasma devices. Experimental results prove that the plasma devices developed have advanced the efficacy of atmospheric-pressure plasma devices by increasing the flux of reactive species from the plasma to the sample. Testing of the developed plasma devices was carried out using optical emission spectroscopy, optical absorption spectroscopy, schlieren imaging and degradation of potassium indigo trisulphonate. Focus in the area of sterilisation using plasmas has triggered many plasma devices to be developed worldwide, each one being tested for efficacy by its home institution. Prior to this work efficacies had to be drawn from many different testing methodologies so direct comparison between plasma devices was problematic. This work proposes a reference protocol of Bacillus subtilis spores filtered onto polycarbonate membranes for the preparation of biological samples to carry out direct comparison of plasma devices for biological inactivation. Atmospheric-pressure plasma systems are a fast-emerging field of engineering research as they obviate the requirement of the costly and bulky vacuum systems required by low pressure plasmas. A wide range of applications such as medical treatments, surface sterilisation and aerodynamic flow control have recently been emerging in the literature, presenting exciting opportunities for new plasma devices or treatment methods to be brought to the forefront. These plasmas offer an alternative to existing applications such as cleaning or chemical production as they hold the advantage that they do not require any other chemicals such as bleach, the only input to the system being power and air. Plasmas can be utilised in so many applications because of the clever design of the devices that create them, most applications require a new design configuration in order to optimise the plasma for each case. As with many fields, developments are required in the efficiency, cost, efficacy and size of said plasma devices. Experimental results prove that the plasma devices developed have advanced the efficacy of atmospheric-pressure plasma devices by increasing the flux of reactive species from the plasma to the sample. Testing of the developed plasma devices was carried out using optical emission spectroscopy, optical absorption spectroscopy, schlieren imaging and degradation of potassium indigo trisulphonate. Focus in the area of sterilisation using plasmas has triggered many plasma devices to be developed worldwide, each one being tested for efficacy by its home institution. Prior to this work efficacies had to be drawn from many different testing methodologies so direct comparison between plasma devices was problematic. This work proposes a reference protocol of Bacillus subtilis spores filtered onto polycarbonate membranes for the preparation of biological samples to carry out direct comparison of plasma devices for biological inactivation.

Cyclic deformation, oxidation damage and fatigue crack growth in nickel-based superalloys have been studied. Strain-controlled low cycle fatigue tests showed strong anisotropy and strain-rate dependency for a directionally solidified alloy. Essentially, the material showed different stiffness and fatigue life when the loading direction was changed from parallel to normal to the solidification direction. Imposition of dwells at peak strain level resulted in stress relaxation. Stabilised evolution of stress amplitude up to failure indicated limited cyclic softening/hardening. Crystal plasticity modelling was carried out to simulate cyclic deformation of the material, using finite element models developed from EBSD analysis of failed specimens. The model showed good predictive capability for the observed low cycle fatigue behaviour. To explain the reduced fatigue life in specimens loaded normal to the solidification direction, a study of stress distribution was conducted using the finite element crystal plasticity model. It was discovered that grain misorientations arising from a cluster of smaller grains caused severe localised stress concentrations, leading to earlier crack initiation and shortened fatigue life. Oxidation damage of single crystal and directionally solidified alloys was studied by testing thin disc specimens under isothermal conditions. Oxidation kinetics was assessed based on thermogravimetric analysis data. To analyse oxidised specimens, focused-ion beam (FIB) sectioning, complemented by SEM-EDS/EDAX analyses, was carried out. Oxidation was evident in the growth of both surface and internal oxides. This resulted in chemical composition changes near exposed surfaces and consequently led to microstructure change due to dissolution of γ'-precipitates. Load-controlled nano-indentation testing was used to rationalise microstructure change due to oxidation damage. At continuum level, deformation of a crack tip subjected to fatigue loading in vacuum and air was studied using finite element simulations for a polycrystalline alloy. In vacuum, material damage was purely mechanical and therefore, described by accumulated plastic strain. In air, a diffusion-based approach was developed and applied to investigate the interaction between fatigue loading and oxygen penetration at a crack tip. For selected loading conditions, progressive increase in oxygen concentration with fatigue cycles was evident. A local compressive stress due to dilatation effect was induced, which compensated part of the tensile stress caused by mechanical loading. A crack-growth criterion based on accumulated plastic strain and oxygen concentration at the crack tip was, therefore, developed to predict the crack growth rates under fatigue-oxidation conditions, in comparison against experimental results. Application of the diffusion-based approach was finally extended to a directionally solidified superalloy. To consider the effects of microstructure, grain-structures and textures were taken into account in the model, from which the influence of grain orientations on crack tip deformation and crack growth behaviour was studied. Again, the approach was able to quantify the different crack growth behaviour in vacuum and air conditions.

Silicon carbide (SiC) is a crystalline material and exhibits superior mechanical properties and excellent chemical inertness. Consequently, it has been used in various applications which require high durability and strength. Despite the extensive efforts made in investigating the mechanical behaviour of SiC, there are several research gaps which require continuous attention and further research effort. Particularly, the failure mechanism, impact-induced plasticity and deformation behaviour across length scales are not fully understood for SiC. In addition, SiC was proposed as a candidate structural material for nuclear fusion reactor core, and therefore it is of importance to study its resistance to high-dose irradiation damage. The aim of this research was to provide a systematic understanding of deformation characteristics of SiC using various experimental techniques and microscopy tools, with focus on the effects of loading rate, varying length scales and irradiation. Firstly, quasi-static compression tests were conducted to illustrate the basic failure mechanism and to obtain the mechanical properties such as elastic modulus and compressive strength of the material. To explore the strain rate effect, dynamic compression tests were carried out using split Hopkinson pressure bar, and the rate-dependent compressive strength and fragmentation were studied with the aid of post-test microscopic analyses. In order to characterise the mechanical properties of SiC across length scale, indentation experiments were carried out at different load levels, with a specific interest in grain orientation and indentation size effects. To study the potential application of SiC in nuclear fusion reactor core, focused ion beam (FIB) was used as an efficient and time-saving technique to introduce irradiation damage to the material, followed by nanoindentation and microscopic characterisation. The study revealed that both compressive strength and the fragmentation of SiC were dependent on the applied loading rate. In addition, dislocation-associated plastic deformation was observed under high strain rate loading conditions. On the other hand, the mechanical behaviour of SiC was also found dependent on the grain orientation, including the force-displacement response, fracture toughness as well as the hardness and elastic modulus. In addition, size and length scale effects were observed during the indentation experiments performed at a range of load levels. Furthermore, for SiC subjected to irradiation damage, increased hardness and embrittlement were seen for nanoindentations made at low load levels; whereas an overall decreased hardness and strengthened toughness were observed for nanoindentations made at high load levels. To summarise, evident strain rate sensitivity was observed for SiC, with plastic deformation believed to be inertially induced due to geometric confinement during dynamic loading. Grain orientation played an intrinsic role in defining the mechanical response of SiC at nanoscale. In addition, the size effect was attributed to two deformation mechanisms which are associated with strain gradient and defect populations. The response of SiC subjected to irradiation damage was found to be determined by the microstructural variations caused by irradiation, represented by a shallow Ga ion layer on the surface, an amorphous layer in the middle and the substrate underneath.

This thesis reports on research undertaken to investigate how to advance the current practices of resource efficiency and sustainability consideration in manufacturing business through the simultaneous design of Product and Production System (P&PS). The primary objective of this research is the development of a framework and methods to support a manufacturer to transform the current independent design processes into a single design process facilitating designs of resource-efficient P&PS. The research contributed in this thesis is structured into three major parts. The first part reports the literature reviewed to define and refine the key objectives of this research. In this review part, the basic knowledge and current practices of Product Design (PD), Production System Design (PSD), Integrated Design (ID) and Sustainable Design (SD) are explored in order to understand the shortcoming of ID and SD. It has been discovered that current ID practice was to facilitate information exchange between the design process. In which majority of the integrated consideration was conducted to succeed the conventional design targets (i.e. reducing design cost, shortening development time and improving manufacturability of design) than the contemporary targets such as increasing resource efficiency through sustainability consideration. While the current practices of SD often return only an incremental benefit because of the inabilities to access information and to assess sustainable decisions between PD and PSD processes. Moreover, the current practice of ID through information exchange is not sufficient to initiate these abilities which can be performed via a collaborative design process. Thus, there is a need to shift a current integrated practice between individual design processes into a single combined process for designing resource-efficient P&PS at once. In response, the second part of this research introduces a framework for co-designing product and production system, which assist companies in transforming their current independent design process into a single process for designing resource-efficient products and production systems simultaneously. The framework offers methods to study the feasibility of collaborative design adoption and to specify the potentially collaborative decisions within PD and PSD processes. Based on the identified decisions, the optional strategies are recommended to create a customised P&PS design process for the companies with the different design needs. Lastly, the third part of the thesis describes the case studies conducted to demonstrate the implementation and refine the applicability of this framework. These are demonstrated through a simple product designed by an in-house designer and a complex product designed by internal and external designers. The results were used to improve the framework and methods for the wide-ranging implementation. In summary, the research reported in this thesis has concluded that the present ID practice via individual design processes is insufficient to deal with the recent requirement of sustainability. This highlights the importance of enabling a collaborative process for designing and assessing both P&PS together in order to improve environmental benefit. A systematic framework to visualise the benefit of collaborative design, to identify the collaborative consideration and to create a single design process provides to offer opportunities to create P&PS with more efficient use of resources.

Contemporary customers seek products that meet their emotional needs as well as performing an anticipated function. The existing process of evaluating customers' emotional requirements in a Kansei engineering system (KES), however, cannot fully reflect the user experience (UX), particularly for those products that involve physical interactions. Therefore, the research aim of this thesis is to apply KES for sports equipment design using bicycles as a case study. After conducting a thorough literature review and interviewing regular road cyclists, the thesis proposes a so-called UX-based collection method (UXCM).

Hydrogen can potentially become a major energy vector and/or energy store in many future scenarios but is constrained by relatively poor energy-storage-use conversion efficiencies and an uncertain 'green' credibility. Identification of methods for increasing hydrogen production efficiency would have significant benefits. It is known that commencement of electrolysis occurs at optimum efficiency; this is quickly subdued by the onset of loss mechanisms. Also, operating at high voltage would be advantageous because the consequence is higher electrode surface current density or smaller electrode area, either of which directly reduces hydrogen production cost due to plant amortisation; however, increasing voltage increasingly leads to heightened losses. This thesis hypothesises that it may be possible to operate at high voltage whilst retaining the optimum efficiency level by operating intermittently, i.e. by using pulsed power, thereby pre-empting and minimising loss onset. That is, pulsed power will not enhance efficiency per se, it will recuperate or pre-empt heightened losses incurred when attempting to operate at DC voltages substantially above conventional values. In this way, this thesis addresses the question, "can pulsed power be used to enhance aqueous electrolysis hydrogen production efficiency?" The topic has not hitherto been comprehensively and systematically studied. This thesis reviews previous and current hydrogen research but finds a lack of relevant activity. This thesis reviews analytical electrochemical models but finds none that are capable of direct application to the pulsed power situation. Conventional models are substantially empirical and embody statistically averaging thermodynamics. This thesis reviews atomic level simulation modelling, as an approach to gain insight into pulsed power electrolysis, and finds that physically accurate simulations can accommodate as few as 64 atoms over an extremely short time span, but can provide useful insights. There is therefore no prospect of creating an accurate model of a practical scale electrolyser covering a useful time period using this approach. A set of equipment was designed, constructed and tested, comprising voltagemultiplier-based variable power supply, variable timing switch, mixed-gas low-flow volume measurement meter and variable geometry electrolysis cell. The power supply was found to require careful impedance matching to the load while the pulse generator required additional flexibility over frequency of operation. It was determined the overall electrolyser design restricted maximum operating efficiencies. The real and reactive behaviour of the cell was tested at frequencies between 20 Hz and 200 kHz using Electrochemical Impedance Spectroscopy methodology via an LCR bridge meter. The essentially capacitive nature of an aqueous parallel plate electrolyser was examined and capacitance was found to approach zero at higher frequencies. Voltage-current phase was found to change significantly between zero and -90° against frequency; the frequency of the transition varied with electrolyte conductivity and electrode spacing. Impedance was found to approach a low value at high frequency regardless of conductivity or separation but some 'high frequencies' at some conditions were beyond the range of the LCR bridge so behaviour was inferred to be consistent with other conditions. Re-stated: the impedance of low conductivity solutions at high frequency was found to become as low as that of high conductivity solutions at high frequency, which was generally lower than that at low frequency. The EIS method was assessed to determine whether it could provide a useful predictor of electrolyser operation at high voltage by comparing low voltage AC impedance from the EIS analysis against high voltage impedance calculated using a Fast Fourier Transform analysis of the voltage and current oscillograms recorded during efficiency testing. It was found that the effect of temperature variation during efficiency testing swamped the data such that the assessment was inconclusive. The basic energy conversion efficiency was measured for a selection of electrolyte concentrations, electrode separations and current densities and directly compared for pulsed and continuous DC operation. Performance was not found to differ significantly between pulsed power compared to DC power. It is proposed that this is because the operating conditions achieved represented simple 'interrupted-DC' electrolysis; the operating regime where high voltage pulsed electrolysis might transition to an enhanced efficiency mode was not achieved. A DC characterisation provided I-V curves which confirmed the expected transition was not surpassed. A method to mitigate the losses attributed to high voltage electrolysis by pulsed application was not discovered within the test conditions achieved but the high frequency reduction in impedance demonstrates this may be a viable method to pursue.

This thesis details the investigation of relationships between football players' perceptions and the properties of footballs. Through continuous investment in the sport, a highly competitive market for footballs has emerged. In order to improve performance characteristics and differentiate from competitors, there have been radical changes to the materials and constructions used in footballs in recent years, resulting in players commenting on football behaviour in scientific studies and the media alike. Whilst it is evident that players regularly perceive differences between footballs, it is unknown what ball properties relate to different perceptions. To explore the vast landscape between consumer and product, a theoretical framework was used facilitating a structured approach to research. After reviewing product development frameworks, a novel human-product interaction framework incorporating perception was developed. The framework headings were populated for players' perceptions of weight and hardness, both of which are more commonly reported in literature. A series of experiments was carried out evaluating the relationships between players' perceptions of weight and hardness, and football properties. Players' perceivable difference thresholds in respect to ball properties were first investigated, prior to evaluating the contribution of multiple ball properties towards perceived weight and hardness for several match relevant player-ball interactions. Multiple linear regression models were derived, suggesting the influence of several ball properties towards players' perceptions. The regression models were then evaluated through prediction of weight and hardness of a second set of footballs differing in construction and materials. Universal equations for weight and hardness were developed through an optimisation exercise, with the aim of facilitating improved development of future football products. A combination of mass and stiffness metrics corresponded well to perceived weight, whilst several measures of stiffness corresponded well to perceived hardness. A final experiment was performed investigating the contribution of the human senses towards human perception of weight for two separate ball sets, demonstrating a means for designers to better understand how the consumer formulates a perception of a footballs.

Ultrasonic Additive Manufacturing (UAM) is a hybrid metal additive manufacturing process, based on the layer-by-layer ultrasonic welding of thin metal foils and the periodic CNC machining of the bonded layers to achieve the desired three-dimensional geometry. Bonding in UAM occurs in the solid state and at low temperature, making UAM a potential technology for embedding electronic circuitry into metal structures. Printed Electronics (PE) is a family of processes that can fabricate electronic circuitry and components by directly dispensing functional materials onto a substrate. PE technologies have a high potential for integration with additive manufacturing processes, as they both follow similar basic manufacturing principles. Such integration can enable the fabrication of multi-functional parts with embedded electronic circuitry.

Cells respond to mechanical changes in their extracellular environment, as reflected by various cell behaviours and observed through changes in the tissue biomechanics. Types of cell behaviour that are regulated by mechanical cues in the microenvironment of the cell are cell spreading, migration, proliferation and differentiation. Cell migration is a key part of many biological processes including corneal wound repair. Changes in the biomechanical properties of the cornea can be induced by refractive and therapeutic treatments and also by diseases of the eye or other illnesses. A Rabbit Corneal Epithelial (RCE) cell line was used to study cell mechanics and cell migration. Polydimethylsiloxane (PDMS), a biocompatible silicone elastomer, was used as a substrate to culture RCE cells. In order to promote cell attachment and growth, the hydrophilicity of the PDMS surface was increased by treating it with oxygen-rich cold atmospheric pressure plasma, which was confirmed by surface characterisation techniques. Cell attachment and growth studies over time comparing plasma and non-plasma treated PDMS showed an increase in RCE cell growth and area coverage on plasma treated PDMS.

Measurement of biomolecular interactions are widely used in various sectors including life sciences, pharmaceutical, clinical diagnostics, and industrial, food and environmental monitoring. The shifts in resonant frequency and dissipation of mechanical resonators have been extensively used for biomolecular measurements. Conventional resonant frequency and dissipation measurement techniques are largely limited in terms of simplicity, time resolution and potentials for on-chip integration and multiplexability. This PhD research focused on the development of a simple method for quantification of resonant frequency and dissipation shifts of a mechanical resonator, which could potentially allow system-integrable and multiplexable biomolecular measurements with high time resolution. A quartz crystal resonator was chosen as a model mechanical resonator due to its wide applicability. Analytical expressions obtained utilising Butterworth Van Dyke model allowed real-time measurements of resonant frequency and dissipation from each acquired impedance data point at a fixed frequency and amplitude. The method is suited over a broad resonance bandwidth. Quantitative validations were performed against frequency sweep method for inertial and viscous loading experiments using a 14.3 MHz quartz crystal resonator. Resonant frequency shifts related to temporal steps of quick needle touches on a selfassembled-monolayer-functionalised 14.3 MHz quartz crystal resonator surface were estimated with a time resolution of 112 s, which is nearly hundred times smaller than the reported time resolution in the quartz crystal microbalance literature. The fixed frequency drive method has been utilised for demonstration of label-free detection of a gram negative bacterial infection biomarker namely N-hexanoyl-L-Homoserine lactone (~199.2 Da), using molecular imprinted polymer nanoparticles as the receptor. The feasibility of the method has also been tested for direct detection of a large immunoprotein such as immunoglobulin E (~190 kDa), using an aptamer as the receptor. This fixed frequency based method for determination of resonant frequency and dissipation of a mechanical resonator, with no need for averaging, fitting or measurement dead time, potentially allows a simple and low-cost method suitable for integration into online or miniaturised system with significantly improved time resolution and multiplexability.

Research into the development and implementation of Cyber-Physical Systems (CPSs) for Returnable Transit Items (RTIs) is presented in this thesis. CPSs are becoming a significant research focus emanating from advancements in technologies such as the Internet of Things (IoT), Cloud Manufacturing and Intelligent Products. This advancement in manufacturing is touted to bring about a step change in manufacturing efficiency, flexibility and production yield that it has been discussed as a potential fourth industrial revolution, coined Industry 4.0. It has been highlighted that there is a lack of documented CPS deployments within industrial setting, including necessary CPS design, development and deployment tools and methodologies. For CPSs to be adopted within industry, it is imperative that robust system architectures and design methodologies are developed to support the requirements of industry. This research's presents new knowledge in the form of functional, knowledge, information and data requirements for CPSs in the automotive manufacturing domain and RTI management. To address the needs this research presents two CPS implementations that reflect different levels of product intelligence, (i) a "low intelligence" RTI within a portal infrastructure and (ii) and intelligent RTI that interacts with other intelligent products and monitors the environment in which it exists. As part of these CPS deployments, this research presents a CPS reference architecture for the typology of CPS components (such as service implementations, asset layer devices and business process activities) and an RTI traceability development methodology for the implementation of Radio Frequency Identification (RFID) technology. From these implementations it was determined that a "low intelligence" RTI can meet 72.7% of stakeholder requirements with an intelligent container capable of meeting 94.6% of these needs. The challenges associated with CPS in the automotive domain were identified to include (i) a lack of RFID traceability application methodologies, (ii) difficulties in capturing and maintaining an understanding of business processes, (iii) a lack of knowledge for designing with product intelligence in mind and (iv) determining the relevance of perceived environmental conditions and its context. The research also highlighted a number of generic CPS components that can be re-used within other CPS deployments and domains, these include (i) an RFID analysis methodology and software application for data collection, (ii) an RFID portal hardware implementation built upon a robust industrial controller (Siemens S7), (iii) a novel intelligent container hardware platform known as smaRTI that integrates a UHF RFID interrogator, environmental sensors and wireless communications and (iv) a number of novel RTI context determination services.

Torsional vibrations generated by the internal combustion engines are transmitted to the drivetrain inducing a plethora of noise, vibration and harshness (NVH) concerns such as transmission gear rattle, clutch in-cycle vibration, judder, to name but a few. The main elements of these oscillations are variations in the inertial imbalance and the constituents of combustion power torque, collectively referred to as engine order vibrations. To attenuate the effect of these transmitted vibrations and their oscillatory effects in the drivetrain system, a host of palliative measures are employed in practice, such as clutch pre-dampers, dual mass flywheel, centrifugal pendulum absorbers and others, all of which operate effectively over a narrow range of frequencies and have various unintended repercussions. These included increased powertrain inertia, installation package and cost. This thesis focuses on the systematic study of incorporating nonlinear energy sink (NES) in the vehicle drivetrain with the aim to attenuate torsional vibrations over a broad range of frequencies and under transient vehicle manoeuvres. The nonlinear energy sink operate on the principle of Targeted Energy Transfer (TET) whereby the mechanical vibration energy from a primary system is transferred in a nearly irreversible way to the secondary system where it is either absorbed, re-distributed or dissipated locally through structural damping. The numerical model of a reduced order drivetrain was developed in MATLAB/Simulink and was validated in both time and frequency domain against the experimental measurements obtained from a test vehicle. Once the validity of the model is established and correlated, the numerical model is modified to incorporate a nonlinear energy sink characterised by smooth and non-smooth nonlinearities. A metric was defined to ascertain the effectiveness of the NES, whereby the difference between the acceleration amplitudes of the 1.5 EO of the transmission input shaft for locked and active system are computed. Through parametric study of the drivetrain with NES, it was conjectured that the NES would lead to significant vibration attenuation over a broad range of 1.5 EO frequencies for various transient manoeuvres, thus being robust to input excitation changes. Following the parametric study of the drivetrain with the NES, a concept absorber was manufactured and tested on an engine-powertrain rig and also on a small scale rig where an electric motor along with universal joint is used to induce the harmonic oscillations in the NES. The conclusion from the engine-powertrain testing are that the NES could not induce into TET due to the active control of the torsional vibrations by the dynamometer, thus limiting the torsional oscillations in the powertrain. In order to resolve this drawback, an electric motor with universal joint is used to induce vibrations in the Clutch-NES system. The NES did engage in Targeted Energy Transfer with the primary system (electric motor) demonstrating vibration attenuation, with the experimental measurements correlating the numerical model observations of the phenomenon.

Atmospheric pressure plasmas have been applied to a multitude of liquid-based applications such as wound healing, combustion, surface cleaning and small-scale chemical processing. For most of the applications, a plasma jet placed above the liquid is favoured, that is typically supplied with argon or helium. For large-scale processes such as wastewater or biomass pretreatment, localised plasma jets become uneconomical and inefficient. In the work presented in this thesis, a novel microbubbleenhanced DBD plasma reactor is presented which allows efficient transfer of highly reactive species from the plasma to a liquid medium. This novel design allows the discharge to be formed in the immediate vicinity of the gas-liquid interface enabling effective mass transfer of short-lived species. The reactor was characterised in the first instance to evaluate and optimize its performance by varying all the input parameters. These studies include understanding the effect of the bubble size, input gas composition and input power supply. The reactive species generated in the gas phase were measured using absorption spectroscopy, and the liquid phase concentrations of the reactive species were measured using a variety of chemical probes. By modelling the reactor, a more in-depth analysis was carried out by tracking the short-lived species over a high time resolution. This led to improvements in efficiency by selecting the optimum operating conditions depending on the plasma chemistry required. As one of the key reactive species is ozone, being able to quantify this concentration in the liquid phase with both precision and accuracy is essential. This led to the development of a selective chemical probe and measurements made with this new probe were compared against existing measurement techniques. The reactor was then applied to several applications including pretreatment of lignocellulosic biomass, pretreatment of anaerobic digester feed and treatment of final wastewater effluent. Treatment of lignocellulosic biomass is often required to break apart the structure to ease the conversion of biomass feedstock to a fuel, usually facilitated by enzymes or bacteria. By treating a suspension of biomass within the reactor, the reactive species transferred to the solution attack the structure increasing the yield of either biogas or ethanol depending on the process applied. Limitations of this approach to pretreatment were identified and future improvements were suggested. When treating a solution contaminated with E. coli, the oxidative species were found to be highly effective in inactivation of the bacteria. The presence of organic matter such as humic acid can significantly reduce the inactivation rate as they consumed the reactive species with competing reactions.