Search

In recent years, the development of worm-like robots has increased significantly. These robots use peristaltic motion comprised of radial expansion and axial elongation to move leglessly through their environments. Soft worm-like robots have the advantage of conforming to their environment, making them ideal for confined spaces such as pipelines which are essential to societal infrastructure. Pipeline contamination and corrosion can be detrimental and costly and thus regular checking is vital. Some pipes are difficult to access due to size, access restrictions and harmful waste contamination (such as in nuclear power plants). This has led to an increase of research into soft worm-like robots for pipe inspection. This review will analyse the recent progress in this area to assess current robotic capabilities and where work may be further needed to ensure they are applicable to real-world applications.

Bone regeneration by tissue engineering has extensively employed hydroxyapatite (HA) for bone regeneration due to its positive biological properties. However, the high crystallinity of commercial HA results in a slower biodegradation rate. This study explored the incorporation of pearl powder with calcium phosphate. Two successful synthesis methods yielded pearl/CaP composite particles with different crystallinity, confirmed through XRD patterns. Physiochemical evaluations, including TGA, FTIR, Raman spectroscopy, XRD, XPS, and SEM, provided a comprehensive understanding of structural aspects, revealing chemical bonding between pearl and HA particles. FTIR-PAS results confirmed the presence of both A and B types of carbonated HA. Integration of these particles with chitosan (CS) through freeze-drying produced composite scaffolds with enhanced compressive strength and improved cytocompatibility compared to HA-based CS scaffolds. In vitro cell culture analyses demonstrated a higher proliferation ratio for p/CaP composite scaffolds, especially a 30:70 pearl to CaP ratio. SEM analysis corroborated the positive crosslinking and osteogenesis performance of these scaffolds, emphasizing their potential in bone tissue engineering. However, scaffolds with a high pearl: CaP ratio (50:50) and elevated p/CaP concentrations (50 wt.%) exhibited poor or non-osteogenic behaviour, underscoring the importance of carefully balanced pearl: CaP ratios and p/CaP concentrations for effective osteogenesis.

A mini review covering mold casting of metal-based materials via the Shaw process. Ceramic mold casting refers to metal casting processes that employ ceramics as the mold material. The Shaw process and the Unicast process are types of ceramic mold casting that are used to manufacture items (e.g. golf clubs, impellers, etc.) from low to high volume, and from small to large tonnage. This mini review covers the academic and patent literature that focus on metal casting via the Shaw process.

A compact back-end interface for silicon photomultipliers (SiPMs) implementing Zener diode-based temperature compensation has been developed for the remote detection of beta and gamma radiation. Remote detection is facilitated by the development of an efficient data management system utilising MySQL database storage for recording periodic spectra data for wireless access over a private Wi-Fi network. A trapezoidal peak shaping algorithm has been implemented on an FPGA for the continuous conversation of pulses from the SiPM, signifying the detection of a radiological particle, into spectra. This system has been designed to fit within a 46 mm cylindrical diameter for in situ characterization, and can be attached to one or more SiPMs used in conjunction with a range of scintillators. LED blink tests have been used to optimise the trapezoidal shaper coefficients to maximise the resolution of the recorded spectra. Experiments with an array of SiPMs integrated with a NaI(Tl) scintillator exposed to sealed sources of Co-60, Cs-137, Na-22 and Am-241 have shown that the detector achieves a peak efficiency of 27.09 ± 0.13% for a gamma peak at 59.54 keV produced by Am-241, and a minimum energy resolution (Delta E/E) of 4.27 ± 1.16% for the 1332.5 keV gamma peak from Co-60.

3D objects with integrated electronics are produced using an additive manufacturing approach relying on multiphoton fabrication (direct laser writing, (DLW)). Conducting polymer-based structures (with micrometer-millimeter scale features) are printed within exemplar matrices, including an elastomer (polydimethylsiloxane, (PDMS)) have been widely investigated for biomedical applications. The fidelity of the printing process in PDMS is assessed by optical coherence tomography, and the conducting polymer structures are demonstrated to be capable of stimulating mouse brain tissue in vitro. Furthermore, the applicability of the approach to printing structures in vivo is demonstrated in live nematodes (Caenorhabditis elegans). These results highlight the potential for such additive manufacturing approaches to produce next-generation advanced material technologies, notably integrated electronics for technical and medical applications (e.g., human-computer interfaces).

Nuclear sites require regular measurements of the air, soil, and groundwater to ensure the safety of the surrounding environment from potentially hazardous levels of contamination. Although high-energy beta and gamma emitters can often be detected instantly using fixed dosimeters, the detection of low-energy beta emitters is a difficult challenge, especially in groundwater, as its radiation is easily self-absorbed by the surrounding medium. Therefore, it is common practice to sample groundwater and transfer it to a laboratory for analysis using Liquid Scintillation Counting. This work demonstrates a new detector design for the real-time monitoring of tritiated water, a weak beta emitter. This design utilizes a flow cell filled with a granulated scintillator to maximize the surface area of the sample. The cavity is made from plastic sheets, which allow rapid manufacture using readily available lamination sheets. A column of SiPMs in coincidence counting mode has been implemented to reduce noise and allow future extensions to the flow cell for greater detection rates while allowing the detector to fit within limited spaces such as groundwater monitoring boreholes. Using multiple concentrations of tritiated water, this detector has been validated and calibrated, obtaining a minimum detection activity of 26.356 ± 0.889 Bq/mL for a 1-day counting period.

Thermoelectric Generators (TEGs) utilise the Seebeck effect which can directly convert heat energy into electricity. When a temperature difference is created across the TEG modules, an electromotive force will be generated if the modules are connected in an electric circuit with a load. As the planet aims to reduce its carbon footprint clean methods of generating electricity are increasing in demand, and therefore so is the research into the use of TEG modules. This research aimed to determine how TEGs could be used in utilising the temperature difference between the inside of a small submarine and the water which surrounds it and predict how much electrical power could be produced. This was done using both Ansys software and physical experiments. A test rig was built to emulate the conditions which would be experienced by the TEG modules in a submarine, with a warmer constant temperature on one side and the other side cooled by flowing chilled water. Many materials and the potential addition of heat transfer fins were tested, and all experimental tests performed were then simulated in Ansys Fluent and Thermal Electric to ascertain how accurate the simulations represent real-world results. The tests were performed from temperatures ranges between approximately 5⁰C ≤ T ≤ 20⁰C, it was decided that all temperatures 17⁰C and below simulated in Ansys would give a fair representation of how much power the TEGs could produce.Using the information from these tests and simulations, scaled up models we simulated in Ansys to model the TEG modules in a submarine section. These results showed that the use of heat transfer fins was not necessary due to the thickness of the submarine wall and the velocity at which the submarine would travel. At a temperature difference of 15⁰C between the inside of the submarine and the water flowing around it, four TEG modules connected in series can be expected to produce 0.35W.

The decommissioning of nuclear sites is a significant and growing engineering challenge often requiring specialist equipment, especially when the nuclear site is partially submerged with contaminated water. However, most currently available decommissioning tools are large, bulky structures that lack dexterity. In this paper, a novel dual-arm continuum robot, which is composed of two 6-degree of freedom (DoF) continuum arms that can be simultaneously employed, is developed. To improve the mechanical performance of the continuum arms, additional compliant mechanisms (flexure hinges) were integrated into its design. By combining the dual-arm continuum robot with a commercial unmanned underwater vehicle (UUV), the system can be deployed in many underwater engineering scenarios to conduct complicated tasks. The prototyped dual-arm continuum robot and its control system has been tested to ascertain its kinematic accuracy. It was found the average displacement error is within 5.7% of the 6-DoF continuum robot (length: 540 mm), proving its potential for high-accuracy operation.

Biomaterials capable of precisely controlling the delivery of agrochemicals/biologics/drugs/fragrances have significant markets in the agriscience/healthcare industries. Here, we report the development of degradable electroactive polymers and their application for the controlled delivery of a clinically relevant drug (the anti-inflammatory dexamethasone phosphate, DMP). Electroactive copolymers composed of blocks of polycaprolactone (PCL) and naturally occurring electroactive pyrrole oligomers (e.g., bilirubin, biliverdin, and hemin) were prepared and solution-processed to produce films (optionally doped with DMP). A combination of in silico/in vitro/in vivo studies demonstrated the cytocompatibility of the polymers. The release of DMP in response to the application of an electrical stimulus was observed to be enhanced by ca. 10–30% relative to the passive release from nonstimulated samples in vitro. Such stimuli-responsive biomaterials have the potential for integration devices capable of delivering a variety of molecules for technical/medical applications.

Continuum robots are increasingly being used in industrial and medical applications due to their high number of degrees of freedom (DoF), large workspace and their ability to operate dexterously. However, the positional accuracy of conventional continuum robots with a backbone structure is usually low due to the low stiffness of the often-lengthy driving cables/tendons. Here, this problem has been solved by integrating additional mechanisms with adjustable stiffness within the continuum robot to improve its stiffness and mechanical performance, thus enabling it to be operated with high accuracy and large payloads. To support the prediction of the improved performance of the adjustable stiffness continuum robot, a kinetostatic model was developed by considering the generalized internal loads that are caused by the deformation of the flexure-hinge mechanism and the structural stiffening caused by the external loads on the end-effector. Finally, experiments were conducted on physical prototypes of 2-DoF and 6-DoF continuum robots to validate the model. It was found that the proposed kinetostatic model validates experimental observations within an average deviation of 9.1% and 6.2% for the 2-DoF and 6-DoF continuum robots, respectively. It was also found that the kinematic accuracy of the continuum robots can be improved by a factor of 32.8 by adding the adjustable stiffness mechanisms.

Introduction The rapid development of wearable/implantable electronic devices for biomedical applications is exciting. Telemedicine methods of personal identification and/or patient medical information directly embedded within an individual may revolutionise civilian/military healthcare, motivating the development of minimally invasive methods to print a variety of components in vivo. Potential applications include electronic devices for communications or identification, or optically-readable tags, such as barcodes and QR codes for data storage, personnel identification or medical history. Method We utilise a novel photochemical approach for the additive manufacture of embedded polymer components with wide-ranging biomedical applications, with the demonstrated potential for 3D printing of electronic components in vitro, ex vivo and in vivo. Custom ink formulations are applied/delivered to a substrate (material/tissue/organism) followed by photochemical development of the ink within the substrate yielding de novo designed electronic components within/on the substrate characterised by a variety of analytical methods (e.g., electrical/microscopy/spectroscopy). Results We demonstrate progress towards complex electrical devices, with the fabrication of conductive polymer wires, which can form the foundation of all subsequent larger electrical devices. Subsequently, the successful printing of a functioning quick response (QR) code is demonstrated, enabling information to be embedded and easily characterised. Further measurement of this device with an optical microscope shows the ability to store information ex-vivo with a simple characterisation technique, and shows promise for effective 3D printed devices for medical applications in-vivo. Conclusion Facile printing of devices for electronic characterisation, or optical components for characterisation with a conventional camera paves the way for a next generation of embedded bioelectronics that we foresee revolutionizing

In situ repair and maintenance of high-value industrial equipment is critical if they are to maintain the ability to continue vital operations. Conventional single-arm continuum robots have been proven numerous times to be successful tools for use in repair operations. However, often more than one arm is needed to ensure successful operation within several scenarios; thus, the collaborative operation of multiple arms is required. Here, we present the design and operating principles of a dual-arm continuum robot system designed to perform critical tasks within industrial settings. Here, presented are the design principle of the robotic system, the optimization-based inverse kinematic calculation of the 6-DoF continuum arms, and the collaborative operation strategy. The collaborative principle and algorithms used have been evaluated by a set of experiments to demonstrate the ability of the system to perform in situ machining operations. With the developed prototype and controller, the average error between planned and real toolpaths can be within 2.5 mm.

Drug delivery devices ensure the effective delivery of a broad range of therapeutics to millions of patients worldwide on a daily basis.1 Microneedles are a class of drug delivery device that provide pain free transdermal delivery with improved patient compliance.2-4 The release of metformin, a drug used in the treatment of cancer and diabetes, from polymer hydrogel-based microneedle patches was demonstrated in vitro. Tuning the composition of the polymer hydrogels enabled preparation of robust microneedle patches with mechanical properties such that they would penetrate skin (insertion force of a single microneedle to be ca. 40 N). Swelling experiments conducted at 20°C, 35°C and 60°C show temperature dependent degrees of swelling and kinetics (Fickian diffusion). Drug release from the hydrogel-based microneedles was fitted to various models (e.g., zero order, first order, second order, Korsmeyer-Peppas, Peppas-Sahlins), observing the best fit for the zero-order model. Such microneedles have potential application for transdermal delivery of metformin for the treatment of cancer and diabetes.

In many industries worldwide, decommissioning is a significant and growing engineering challenge requiring specialist tools and robots. This is particularly the case in underwater or submerged nuclear sites, such as the stricken Fukushima Daiichi reactors. However, most currently available decommissioning tools are bulky structures lacking dexterity. In this paper, a novel dual-arm robot, composed of two 6-DoF continuum arms designed to work together, is developed with the intent to collect material samples from underwater environments.

Energy Act 2008 requires that a large proportion of the North Sea infrastructure will need to be decommissioned in the next 30 years. To perform subsea decommissioning activities, technologies which are flexible (there is large heterogeneity in the structures), fast (deployment costs are significant), reliable (to minimise down-time) and deployable remotely (to avoid the use of divers) need to be developed. Underwater laser cutting provides an innovative cutting technology for decommissioning offshore infrastructures and nuclear waste which is cheaper, safer and relatively faster. In this research, three approaches were used to investigate underwater laser cutting of C-Mn steel using a 10 kW fibre laser. These approaches comprise of an experimental, theoretical, and numerical study of underwater laser cutting. The experimental work consisted of underwater laser cutting trials, conducted in a 1m3 tank and a high pressure vessel. The findings for both cutting trials were analysed for the influence of process parameters on performance and cut quality. The cut quality is assessed in terms of the attached dross height and kerf width because the key requirement in decommissioning applications is that the parts being cut must be separated with minimal secondary waste. A 50 mm thick C-Mn steel workpiece was adequately cut with a maximum cutting speed of 200 mm/min for hydrostatic pressure conditions of up to 20 bar, representing a water depth of ~200 m. The process performance and kerf width results predicted by the theoretical model are validated by underwater laser cutting trials carried out in a 1 m3 tank. A key finding in the numerical study of a 3-dimensional (3D) gas jet expansion model is that a mixed phase (water, water vapour (steam) and air) medium was observed at the exit of the virtual kerf along the path of the laser beam.

Clean water is a finite resource, and the quality of such is best monitored by colorimetric in-situ sensors, which allow frequent, non-labour intensive sampling, and are low-cost and simple to manufacture. There are multiple types of sensors that exist in the literature, however, many are cost-prohibitive for wide deployment, or the literature does not not fully elaborate on their operation. The aim of this research was to extend the lifetime and improve the performance of a colorimetric in-situ sensor, Aquamonitrix colorimetric sensor, that was produced by T.E. Laboratories, in addition to characterising sensor behaviour. Its operation was focused on the Griess reaction, in which a vivid azo dye is produced in the presence of nitrite, that can be linearly calibrated to the absorbance by the dye from a photodectector placed at the opposite end of a microfluidic detector channel to a monochromatic light source. Using multiobjective optimisation on a numerical model of a Y-junction micromixer, it was found that both sensitivity could be increased and reagent could be conserved, by limiting the proportion of reagent used during testing to 5% to 7.5% of testing solution, as opposed to the 50% originally used by the system. The conservation of the reagent allowed for an increased sensor deployment lifetime of up to tenfold. To better understand how the parameters of analyte concentration, reagent proportion of test solution, and mean flow velocity of the solution affect sensor output, both mechanistic and data-based modelling of the continuous and stopped flow stages of the sensor were undertaken. Third-order and second-order models were identified for the continuous and stopped flow data respectively. The second-order model is analagous to the two-step Griess reaction, of which there is a first, faster step. Further characterisation of the zeroes, poles and transfer function coefficients of the third order models showed that parameterisation was possible and, using prin