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MXenes are novel 2-D materials which have been extensively investigated for use in advanced biocomposites, water purification, biosensors, bioimaging and antibacterial systems. However, the knowledge associated with the mechanism of cytotoxic response is still limited to lack of verification against 3D spheroid-type cultures. Herein, we present a report on the in vitro cytotoxicity of Ti2CTx MXene against cervical cancer cell lines (HeLa) in a form of 3D spheroid with comparison to 2D cell culture system. Ti2CTx MXenes can be characterized by their multi-layered structure that is produced by the efficient elimination of Al and appearance of the surface functional groups. The biological results with 2D and 3D HeLa indicated that the Ti2CTx MXene was moderately cytotoxic to cells and the cytotoxicity was dose dependent. Our results showed that the toxicity of MXenes is potentially due to direct contact of the Ti2CTx MXene with the cell membrane wall. The Raman spectra suggested that the Ti2CTx MXenes interfered with the cytoplasmic proteins’ conformation and the surrounding microenvironment. This inherently modified the biochemistry of the cell membrane and caused cell apoptosis. This paper contributes to the pool of knowledge regarding the biocompatibility and biophysical properties of Ti2CTx MXene.

Non-thermal atmospheric pressure plasma jet (NTAPPJ) was shown as a promising tool for sterilization, treatment of chronic wounds & tumors. A portable and facile NTAPPJ system will broaden the application of plasma for many other biomedical applications. This paper demonstrates the feasibility of a customized dimmer controllable atmospheric pressure plasma jet (APPJ) in treating HeLa cells. A plasma torch was energized at 8 kVpp and 35 kHz from a neon transformer and discharged with argon gas-producing plasma plume of various gas species. The output intensity of the plasma discharge was adjusted by the voltage input from the dimmer controller circuit. Between 60 – 220 V, a different power output of the dimmer can be varied between 8.4 to 83.6 W, to generate different intensities of non-thermal APPJ (NTAPPJ). The NTAPPJ was then applied to HeLa cells for 20 sec & it was found that cells reduced their adhesion at a dimmer power < 20 W but stayed viable. This progressed to observations of damaged cell body when the power was increased beyond 20 W & the cell membranes shattered when the power was up to 83.6 W. This was due to the ultraviolet rays and reactive oxygen species (ROS), that induced detrimental effects to the cells. The controllable NTAPPJ system, based on dimmer control, induced different levels of effects on the biophysical structures of cells, ranging from reduced cell spread to apoptosis and eventually cell membrane disintegration.

The embedment of induction loop underground for traffic volume monitoring caused damaging effects to the road and reduced road surface aesthetics. A wireless magnetometer implanted underground in a small uniform area was developed to detect three-axis magnetic flux changes due to the perturbation of vehicle passing over the sensor. In this project, a wireless magnetometer sensor system operating at a radio frequency of 2.4 GHz for detecting and transmitting Z-field data has been developed to investigate the patterns of magnetic field associated with the car directions and speed. This is the first report in revealing the responses of the sensor to different car speed and sensing directions. Field tests were conducted by car passes over in a direction in-line or countering the X and Y axes of the magnetometer. The results showed that the strong magnetic field density as low as -100 to -230 μT could be generated when a car passed over the sensor in a direction countering X and Y axes. The speed detection limit of the sensor is < 60 kmph. The X, Y and Z flux patterns obtained is important in designing an algorithm for accurate detection and counting of vehicles.

Generating a tissue model mimicking the cervix could be useful for studying treatment of precancerous lesions. In this work, bioprinting of hexagon shaped alginate-gelatin scaffolds laden with HeLa spheroids was presented. The three-dimensional (3D) printing system was designed to extrude alginate-gelatin bioink of different viscosities at an extrusion rate of 1–5 mL/min and printing speed from 10 to 50 mm/s. The biophysical properties of the bioink were characterized using dynamic mechanical analysis, viscometer, degradation test, contact angle measurement, Fourier transform infrared spectroscopy (FTIR), live/dead cell stainings and Raman spectroscopy. The bioink formulated with 10% w/v of alginate and 50% w/v of gelatin (ALG10-Gel50) enabled high fidelity printing for the construction of a multilayered 3D structure. The viscosity of the bioink within 12 Pa s and viscoelasticity of the polymerized bioink (G′ = 0.074 MPa > G″ = 0.028 MPa) exhibited mechanical properties close to the in-vivo system. The scaffolds degraded 35% on the day 16 of culture. The polymerized bioinks exhibited hydrophilicity and contained amino groups as characterized by contact angles and FTIR measurements, respectively. In addition, the 3D microtissues laden in the scaffold were indicated with high cell viability at 95.25 ± 1.75% based on the live/dead cell stainings. The printed microtissues were characterized with the presence of deoxyribonucleic acid, lipids and amino acids associated with the collagen. This paper demonstrated the success in the bioprinting of multilayer hexagon shaped tissue model which is potentially useful for development of an in-vitro cervical cancer model.

Bioinks of 3D bioprinting have significant potential application in the field of tissue engineering to support cell attachment and proliferation. In this work, the alginate-gelatin-CELC (AGLC) bioink based on different compositions of alginate-gelatin (AG) hydrogel and cholesteryl ester liquid crystals (CELC) was prepared. Primarily, the alginate-gelatin hydrogel with certain concentration of Gelatin (10-50%w/v) was investigated. The printability of the hydrogel reached a minimum width of 1.8 mm at a flow rate of 1 mL/min when the Gelatin concentration was increased to 50 % w/v (AG1050). Subsequently, the respective polymers with 10% w/v Alginate and50% w/v Gelatin blended with 1%, 5%, 10%, 20%, 40%, and 60% w/v of CELC in the preparation of the alginate-gelatin-CELC bioink was further investigated. The printability of the bioink was examined by micro-extrusion based 3D bioprinter. The printability of the bioink enhanced by 27.8% as compared to AG1050 and reached a minimum width of 1.3 mm at a flow rate of 1 mL/min when the CELC concentration was increased to 40% and 60%. The tested properties of the bioink show that the CELC improve shear-thinning and lipid moieties properties to the composite bioink and hence, enhances its printability.

Although the antibacterial properties of MXene nanosheets containing Ti3C2Tx are known, their antifungal properties have not been well studied. Herein, we present for the first time a report on the antifungal properties of Ti3C2Tx MXene. The Ti3C2Tx MXene was obtained by first exfoliating MAX phase of Ti3AlC2 with concentrated hydrofluoric acid, then the Ti3C2Tx was intercalated and deliminated by ethanol treatment and ultrasonication process. The delaminated Ti3C2Tx MXene nanosheets (d-Ti3C2Tx) were characterized using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), and Raman spectroscopy. It was found that Ti3C2Tx MXene was characterized by lamellar structure alternating with layers of Ti, Al and C. The EDX results revealed that the delaminated Ti3C2Tx MXene nanosheets were composed of Ti, C, Si, O, F, and a trace amount of Al. The XRD and Raman spectra further indicated the elimination of Al and the formation of two-dimensional Ti3C2Tx MXene nanosheets. The antifungal activity of the delaminated Ti3C2Tx MXene was determined against Trichoderma reesei using the modified agar disc method. Observation using inverted phase contrastmicroscopy revealed inhibited fungus growth with the absence of hyphae around the discs treated wtih MXene. The surrounding of the control groups without an inclusion of MXene was found with large number of hyphae and spores. In addition, the spores of the fungi treated with the samples containing d-Ti3C2Tx MXene nanosheets did not germinate even after 11 days of culture. The results demonstrated disruption to the hemispheric structural formation of fungi colony, inhibition of hyphae growth and cell damage for fungi grown on the d-Ti3C2Tx MXene nanosheets. These new findings suggest that d-Ti3C2Tx MXene nanosheets developed in this work could be a promising anti-fungi material.

The discovery of SARS-CoV-2 virus in the water bodies has been reported, and the risk of virus transmission to human via the water route due to poor wastewater management cannot be disregarded. The main source of the virus in water bodies is the sewage network systems which connects to the surface water. Wastewater-based epidemiology has been applied as an early surveillance tool to sense SARS-CoV-2 virus in the sewage network. This review discussed possible transmission routes of the SARS-CoV-2 virus and the challenges of the existing method in detecting the virus in wastewater. One significant challenge for the detection of the virus is that the high virus loading is diluted by the sheer volume of the wastewater. Hence, virus preconcentration from water samples prior to the application of virus assay is essential to accurately detect traceable virus loading. The preparation time, materials and conditions, virus type, recovery percentage, and various virus recovery techniques are comprehensively discussed in this review. The practicability of molecular methods such as Polymer-Chain-Reaction (PCR) for the detection of SARS-CoV-2 in wastewater will be revealed. The conventional virus detection techniques have several shortcomings and the potential of biosensors as an alternative is also considered. Biosensing techniques have also been proposed as an alternative to PCR and have reported detection limits of 10 pg/μl. This review serves to guide the reader on the future designs and development of highly sensitive, robust and, cost effective SARS-CoV-2 lab-on-a-chip biosensors for use in complex wastewater.

MXene based nanomaterial is an uprising two-dimensional material gaining tremendous scientific attentions due to its versatile properties for the applications in electronic devices, power generation, sensors, drug delivery, and biomedicine. However, the cytotoxic effects of MXene still remained a huge concern. Therefore, stringent analysis of biocompatibility of MXene is an essential requirement before introduction to human physiological system. Several in vitro and in vivo toxicological studies have been reported to investigate the interactions between MXenes with living organisms such as microbes, mammalian cells and animal models. The biological response and cytotoxicity reported were dependent on the physicochemical properties of MXene. The biocompatibility and cytotoxicity of MXene were dependent on size, dose, and surface coating. This review demystifies the in vitro and in vivo biocompatibility studies associated with MXene. Various methods proposed to mitigate the cytotoxicity of MXene for in vivo applications were revealed. The machine learning methods were developed to predict the cytotoxicity of experimentally synthesized MXene compounds. Finally, we also discussed the current research gaps of applying MXenes in biomedical interventions.

For the global market to achieve a competitive advantage, the companies in the manufacturing industries are working tirelessly to develop new products and services to meet the people’s demands. As a result, manufacturing companies worldwide are using highly advanced technologies to increase efficiency and effectiveness. Even though these high-end technologies are used in factories, they are not as closely integrated as they should be. This paper aims to review the impact of the Internet of Things (IoT) adoption in Malaysia’s manufacturing industry. The study conducted a rigorous review of the literature on (IoT) in the manufacturing industry. The paper reveals that there is a wide coverage and usage of IoT in the manufacturing industries even though the integration of IoT is at a very early stage. Therefore, the study recommended developing good infrastructures and strategies that will support the use of IoT. This will improve the efficiency and effectiveness of this highly relevant and essential sector.

It is reported that the prevalence of obesity and overweight among the teenagers is at alarming level. Obesity might develop into further health issues as they grow up into adults. Better lifestyle and modern technologies such as internet and smart phones have encouraged sedentary lifestyle. Lack of physical activities and uncontrolled food intake would be the main causes. The project aims at developing a portable internet-of-thing (IoT) instrument to monitor their physical activities. The instrument is designed to wrap around the arm and is a battery-powered microcontroller system, equipped with a global-positioning-system (GPS) sensor and a movement sensor (accelerometer). The system would synchronize to the internet via a smart phone. The location and body movements are recorded and could be monitored remotely by another user.

MXene is a recently emerged multifaceted two-dimensional (2D) material that is made up of surface-modified carbide, providing its flexibility and variable composition. They consist of layers of early transition metals (M), interleaved with n layers of carbon or nitrogen (denoted as X) and terminated with surface functional groups (denoted as Tx/Tz) with a general formula of Mn+1XnTx, where n = 1–3. In general, MXenes possess an exclusive combination of properties, which include, high electrical conductivity, good mechanical stability, and excellent optical properties. MXenes also exhibit good biological properties, with high surface area for drug loading/delivery, good hydrophilicity for biocompatibility, and other electronic-related properties for computed tomography (CT) scans and magnetic resonance imaging (MRI). Due to the attractive physicochemical and biocompatibility properties, the novel 2D materials have enticed an uprising research interest for application in biomedicine and biotechnology. Although some potential applications of MXenes in biomedicine have been explored recently, the types of MXene applied in the perspective of biomedical engineering and biomedicine are limited to a few, titanium carbide and tantalum carbide families of MXenes. This review paper aims to provide an overview of the structural organization of MXenes, different top-down and bottom-up approaches for synthesis of MXenes, whether they are fluorine-based or fluorine-free etching methods to produce biocompatible MXenes. MXenes can be further modified to enhance the biodegradability and reduce the cytotoxicity of the material for biosensing, cancer theranostics, drug delivery and bio-imaging applications. The antimicrobial activity of MXene and the mechanism of MXenes in damaging the cell membrane were also discussed. Some challenges for in vivo applications, pitfalls, and future outlooks for the deployment of MXene in biomedical devices were demystified. Overall, this review puts into perspective the current advancements and prospects of MXenes in realizing this 2D nanomaterial as a versatile biological tool.

The feasibility of a dimmer and neon transformer to provide power control to the atmospheric pressure plasma jet (APPJ) is presented in this paper. The standard neon transformer was previously shown applicable to power up a plasma torch to generate plasma irradiation of an APPJ at 8.64kv and 35kHz. However, the plasma emission is not controllable. In this study, a lamp dimmer was proposed to function as a power controller to the neon transformer which drives the generation of plasma and discharged with argon gas. With the dimmer output voltage adjustable from 60 - 220V, the power and current of the dimmer were variable from 8.4 to 83.6 W and 0.08 and 0.38 A, respectively. The temperature measured at the quartz tube and sample exposure site were less than 50oC suggested that the APPJ produced were non-thermal. A simple test by exposing plasma plume to a leaf sample showed that the plasma produced were non-damaging to the leaf. This portable system can provide control to the APPJ and applicable for bioengineering studies.

Monitoring current supplies to light emitting diode (LED) luminaires is one of the reliability tests performed manually. Bluetooth (HC-05) embedded digital ammeter was proposed to acquire currents of a badge of LED products and hence, quality can be assured. Android App was designed to remotely record the current supplies to the different models of LED products and checking if the current measured is within the allowed range. The current data can be further analysed to control the quality of the LED luminaires produced. The pass and fail-current range can be set in the digital ammeter for alerting abnormal current measured by the operator. Therefore, IOT embedded digital ammeter will help in monitoring data consistency of LED products and improve quality assurance procedure.

3D Bio-printer is said to have potential in the applications of medical studies and tissue engineering. A 3D Bio-printer could be used to print the artificial organs for organs transplant and cell tissue culture for generating new cell tissue. It could help in future medical and biological research. This paper presents the development process, i.e. working principle of Fused Deposition Modelling (FDM), mechanical, electrical and related applied software, of a 3D Bio-printer using syringe-based extruder and Core XY mechanism. Up to date, FDM is a popular technique because it is easily implemented, precise and accurate. The printed product revealed high repeativity, where (sample mean, sample standard deviation) is ( mm. The procedure could help future customized 3D Bio-printer.

3D microtissue models, especially cancer microtissue model, are potentially applicable for new drug testing because 3D microtissue reveals more realistic drug response, characterizes the disease and mimics the tumor in human body. In this paper, we report the integration of oral squamous cell carcinoma (OSCC) cell line (ORL-48) into 3D microtissue after two weeks of microencapsulation in calcium alginate microbeads that were produced based on the flicking technique. The microtissues contained highly proliferative cells as indicated by Alamar blue assay. The viable microtissues formed were extracted from the calcium alginate shell by means of alginate lyase. As revealed by field emission scanning electron microscopy (FE-SEM), the extracted 3D microtissues were characterized by inhomogeneous microtissue surface but good cell integrity via self-secreted extracellular matrix proteins. DAPI staining showed the proliferative behavior of cells in multilayer structure. These microtissues were able to spread into 2D monolayer after being transferred to grow on petri dishes. The 3D cultured microtissues of ORL-48 could be potentially useful for cancer therapeutic drug assessment in-vitro.

This paper presents the development of an ultrasonic tomography system for multiphase flow imaging. Ultrasonic tomography (UT) modality has a hard-field sensing principle which makes feasible to measure liquid-gas, liquid-liquid and liquid-solid flow composition within a pipe vessel. The sensor configuration for the UT system is discussed along with its signal conditioning circuitry and image reconstruction technique. The feasibility of the system is experimentally carried out on a 100 mm acrylic pipe for a stratified multiphase flow measurement to reconstruct tomographic images.

Computer vision plays an important role in autonomous vehicle, robotics and manufacturing fields. Depth perception in computer vision requires stereo vision, or fuse together a single camera with other depth sensors such as radar and Lidar. Depth from focus using adjustable lens has not been applied in autonomous vehicle. The goal of this paper is to investigate the application of depth from focus for oncoming vehicle detection. Liquid lens is used to adjust optical power while acquiring images with the camera. The distance of the oncoming vehicle can be estimated by measuring the oncoming vehicle’s sharpness in the images with known lens settings. The results show the system detecting oncoming vehicle at ±2 meter and ±4 meter using depth from focus technique. Estimation of oncoming vehicles above 4 meter can be done by analysing the relative size of the vehicle detected.

We describe a new scaffold-free three-dimensional (3D) cell culture model using cholesteryl ester based lyotropic liquid crystal (LC) substrates. Keratinocytes were deposited randomly on the LC surface where they self-assembled into 3D microtissues or keratinospheroids. The cell density required to form spheroids was optimized. We investigated cell viability using dead/live cell assays. The adhesion characteristics of cells within the microtissues were determined using histological sectioning and immunofluorescence staining. Fourier transform infrared spectroscopy (FTIR) was used to characterize the biochemistry of the keratinospheroids. We found that both cells and microtissues could migrate on the LC surface. The viability study indicated approximately 80% viability of cells in the microtissues up to 20 days of culture. Strong intercellular adhesion was observed in the stratification of the multi-layered microspheroids using field emission-scanning electron microscopy (FE-SEM) and histochemical staining. The cytoskeleton and vinculins of the cells in the microtissues were expressed diffusely, but the microtissues were enriched with lipids and nucleic acids, which indicates close resemblance to the conditions in vivo. The basic 3D culture model based on LC may be used for cell and microtissue migration studies in response to cytochemical treatment.

Microbeads have wide applications in biomedical engineering field that include drug delivery, encapsulation of biomolecules, tissue padding and tissue regeneration. In this paper, we report a simple, yet efficient, flicking technique to produce microcapsules of calcium alginate at a narrow distribution of size. The system consists of an infusion pump and a customised flicker that taps the syringe needle for dispersing microcapsules of sodium alginate that polymerised in the calcium chloride solution. The flow rate of the syringe pump and the velocity of the flicker were studied to achieve a well controlled and tunable size distribution of microbeads ranging from 200 to 400 μm. At a flow rate of 4 μl/min and flicking rate of 80 rpm, a narrow size distribution of microbeads were produced. Via this technique, HaCaT cells were encapsulated in calcium alginate microbeads that grown into microtissues with a size ranging from 100 to 300 μm after two weeks of culture. These microtissues could be potentially useful for pharmacological application.

In a conventional three-dimensional (3D) cell culture system based on microencapsulation, the calcium alginate microcapsules tend to rupture within 7 days of culture, causing unwanted cell leakage. The microencapsulation based on flicking model of calcium-alginate-polyethylene glycol (Ca-alg-PEG) was proposed to rectify this problem. An analytical model to simulate the flicking process based on the deflection of a needle cantilever was also successfully developed and used to predict the size of the microbeads. The size of the microbeads were ranged from 300 to 500 μm and it is controlled by varying the liquid flow rate from 4.8 to 366 μL/min and flicking speed from 70 to 120 rpm. Under a flicking force of 0.58 N, uniform sized and spherical shaped Ca-alginate-PEG microbeads were produced at a liquid flow rate of 40 μL/min and a flicking rate of 100 rpm. The microbeads were characterized by Field Emission Scanning Microscopy, Atomic Force Microscopy, Raman Spectroscopy and Nanoindentation, and the results indicated improved bio-physical properties of the ca-alginate microbeads after added with PEG. The cell viability test demonstrated that Ca-alginate-PEG microbeads were able to support the growth of viable HeLa cells into spheroids. Resilient calcium-alginate-polyethylene glycol (Ca-alg-PEG) microbeads were found to be able to last up to 15 days before rupturing and greatly reduced the cell leakage problem.

The posture monitoring system monitors the posture changes of the upper body and the spinal cord applying to ophthalmologists while operating the slit lamp. The motivation to the pursuit of this system is to relate posture changes while in a static sitting posture to the spinal deviation from the g-line. Often times, the spinal deviation from the g-line is classified as bad posture because of the shift in weight distribution on the spine causing pain and discomfort in certain areas of the spine. This paper presents the design concept, the development process and the working principle of the posture monitoring system using Inertial Measurement Unit (IMU) sensor. The raw measurement data obtained from human trials is tabulated and converted into a graphical representation in which all postures can be identified and distinguished by referring the relative wave pattern. The procedure is important in the improvement on the posture monitoring system for the human trials on the ophthalmologist in future.

Monitoring current supplies to light emitting diode (LED) luminaires is one of the reliability tests performed manually. Bluetooth (HC-05) embedded digital ammeter was proposed to acquire currents of a badge of LED products and hence, quality can be assured. Android App was designed to remotely record the current supplies to the different models of LED products and checking if the current measured is within the allowed range. The current data can be further analysed to control the quality of the LED luminaires produced. The pass and fail-current range can be set in the digital ammeter for alerting abnormal current measured by the operator. Therefore, IOT embedded digital ammeter will help in monitoring data consistency of LED products and improve quality assurance procedure.

The system model is neccessery to be determined in control systems engineering which is generally represented in mathematical form. The mathematical model can be utilized for analysing the system’s characteristics or designing the controller parameters of the system. Here, a neuro model for passive suspension system of a light car is proposed. The candidate structure of the neuro model is contructed from non-linear system of passive suspension of a quarter car mathematical model. Weights estimation of neuro model is conducted by applying iterative weighted least square algorithm. Actual input output data of a test car for training process are acquired by driving the test vehicle on an artificial surface of road. An artificial surface of road is a kind of real road surface imitation. Experimental findings show that the proposed model is able to imitate sucessfully the dynamic properties of the passive suspension system of the light car. The model response shows similar trend and has smallest error.

The human locomotion is studied through gait analysis and is best observed instrumentally rather than observing visually. Thus, a portable insole pressure mapping system is built to assist in studying the human gait cycle. The pressure distribution is determined by instrumentally mapping the insole using force sensitive resistive sensors that are connected to Arduino UNO via cables. The values are saved into a secure digital card that could be post processed. Hardware and software design phase are executed for the development of this project. The outcomes match to the knowledge of human gait definitions in static posture and normal walking.

Growing three dimensional (3D) cells is an emerging research in tissue engineering. Biophysical properties of the 3D cells regulate the cells growth, drug diffusion dynamics and gene expressions. Scaffold based or scaffoldless techniques for 3D cell cultures are rarely being compared in terms of the physical features of the microtissues produced. The biophysical properties of the microtissues cultured using scaffold based microencapsulation by flicking and scaffoldless liquid crystal (LC) based techniques were characterized. Flicking technique produced high yield and highly reproducible microtissues of keratinocyte cell lines in alginate microcapsules at approximately 350 ± 12 pieces per culture. However, microtissues grown on the LC substrates yielded at lower quantity of 58 ± 21 pieces per culture. The sizes of the microtissues produced using alginate microcapsules and LC substrates were 250 ± 25 μm and 141 ± 70 μm, respectively. In both techniques, cells remodeled into microtissues via different growth phases and showed good integrity of cells in field-emission scanning microscopy (FE-SEM). Microencapsulation packed the cells in alginate scaffolds of polysaccharides with limited spaces for motility. Whereas, LC substrates allowed the cells to migrate and self-stacking into multilayered structures as revealed by the nuclei stainings. The cells cultured using both techniques were found viable based on the live and dead cell stainings. Stained histological sections showed that both techniques produced cell models that closely replicate the intrinsic physiological conditions. Alginate microcapsulation and LC based techniques produced microtissues containing similar bio-macromolecules but they did not alter the main absorption bands of microtissues as revealed by the Fourier transform infrared spectroscopy. Cell growth, structural organization, morphology and surface structures for 3D microtissues cultured using both techniques appeared to be different and might be suitable for different applications.

Cells encapsulation is a micro-technology widely applied in cell and tissue research, tissue transplantation, and regenerative medicine. In this paper, we proposed a growth of microtissue model for the human keratinocytes (HaCaT) cell line and an oral squamous cell carcinoma (OSCC) cell line (ORL-48) based on a simple aerosol microencapsulation technique. At an extrusion rate of 20 μL/min and air flow rate of 0.3 L/min programmed in the aerosol system, HaCaT and ORL-48 cells in alginate microcapsules were encapsulated in microcapsules with a diameter ranging from 200 to 300 μm. Both cell lines were successfully grown into microtissues in the microcapsules of alginate within 16 days of culture. The microtissues were characterized by using a live/dead cell viability assay, field emission-scanning electron microscopy (FE-SEM), fluorescence staining, and cell re-plating experiments. The microtissues of both cell types were viable after being extracted from the alginate membrane using alginate lyase. However, the microtissues of HaCaT and ORL-48 demonstrated differences in both nucleus size and morphology. The microtissues with re-associated cells in spheroids are potentially useful as a cell model for pharmacological studies.

This paper proposes on the design of a walker for the prevention of falling among elderlies or patients during rehabilitation whenever they use a walker to assist them. Fall happens due to impaired balance or gait problem. The assistive device is designed by applying stability concept and an accelerometric fall detection system is included. The accelerometric fall detection system acts as an alerting device that acquires body accelerometric data and detect fall. Recorded accelerometric data could be useful for further assessment. Structural strength of the walker was verified via iterations of simulation using finite element analysis, before being fabricated. Experiments were conducted to identify the fall patterns using accelerometric data. The design process and detection of fall pattern demonstrates the design of a walker that could support the user without fail and alerts the helper, thus salvaging the users from injuries due to fall and unattended situation.

Ergonomics has gained attention and take into consideration by the workers in the different fields of works recently. It has given a huge impact on the workers comfort which directly affects the work efficiency and productivity. The workers have claimed to suffer from the painful postures and injuries in their workplace. Musculoskeletal disorders (MSDs) is the most common problem frequently reported by the workers. This problem occurs due to the lack of knowledge and alertness from the workers to the ergonomic in their surroundings. This paper intends to review the approaches and instruments used by the previous works of the researchers in the evaluation of the ergonomics. The two main assessment methods often used for ergonomic evaluation are Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA). Popular devices are Inertial Measurement Units (IMU) and Microsoft Kinect.

There are increasing interests in the application of cold atmospheric plasma device for the application in surface science and medical field. Numerous studies focused on the effects of plasma emission onto living organisms. This report presents the application of a power driver circuit for induction of cold atmospheric plasma (CAP). The system consists of a resonant inverter of Zero Voltage Switching (ZVS) circuit powered by a 12Vdc input voltage which is coupled to a flyback transformer in generation of high voltage up to 24.5 kV. The output voltage from the ZVS driver and flyback transformer to the plasma torch (quartz tube) was determined using Falstad circuit simulation. The simulation on the waveforms generated from the ZVS circuit correlated well with the actual voltage measurement at the output of the ZVS circuit. The peak voltage dropped across a parallel capacitor coupled to the flyback transformer is approximately 36 V. The atmospheric pressure plasma jet (APPJ) purged with Argon gas at a flow r...

Over the last two decades, design and fabrication of micromixer have been an emerging trend in research field of microfluidic. Micromixers are generally categorised into two types which are the passive micromixer dependent on pumping energy and active micromixer that relies on external energy to achieve fluid mixing in desired parameters. This paper presents the micromixing simulation of two fluids of different concentrations from two inlets to generate four distinguished concentration gradient of output in four outlets. The blueprint of the micromixer was designed using Solidworks, computer-aided design software. The 2D model design was imported to COMSOL Multiphysics 4.2 to simulate the fluid mixing. The suggested physic modules were applied on the 2D model to aid the fluids dilution and mixing process. Linear dilution was achieved by applying low flow rates to the micromixer.

Microencapsulation technology had been widely used in biological study, drug delivery, cosmetic and also food industry. Previous methods developed for microencapsulation is complex in terms of their design and handling. A simple micro extruder device with vibration mode was developed to microencapsulate HaCaT cells in calcium alginate capsules at 10 to 60 Hz. The microencapsulated cells proliferated and formed into microtissues. Alginate lyase was applied to remove the microtissues from the encapsulation and for studying the cell adhesion in the microtissues. DAPI and live/dead cell stainings were applied to study the organisation and viability of cells, respectively. Via the nuclei staining, it was found that the distance between cells reduced as the incubation period increased. After 15 days of culture, the cells were viable as indicated by the fluorescence green expression of Calcein-AM. Replating experiment indicated that the cells from the microtissues were able to migrate and has the tendency to form monolayer of cells on the culture flask.

The feasibility of a dimmer and neon transformer to provide power control to the atmospheric pressure plasma jet (APPJ) is presented in this paper. The standard neon transformer was previously shown applicable to power up a plasma torch to generate plasma irradiation of an APPJ at 8.64kv and 35kHz. However, the plasma emission is not controllable. In this study, a lamp dimmer was proposed to function as a power controller to the neon transformer which drives the generation of plasma and discharged with argon gas. With the dimmer output voltage adjustable from 60 - 220V, the power and current of the dimmer were variable from 8.4 to 83.6 W and 0.08 and 0.38 A, respectively. The temperature measured at the quartz tube and sample exposure site were less than 50oC suggested that the APPJ produced were non-thermal. A simple test by exposing plasma plume to a leaf sample showed that the plasma produced were non-damaging to the leaf. This portable system can provide control to the APPJ and applicable for bioengineering studies.

Cholesteryl ester liquid crystals were discovered with a new application in sensing traction forces of single cells. The liquid crystal bio-transducer is produced by manual scraping of liquid crystals onto the petri dish, in which the technique is highly subjective to the skill of the user to produce homogeneously spread liquid crystal substrates. This paper describes the development of an apparatus used to produce a liquid crystal substrate using squeegee coating technique. It consists of a biaxial mechatronic system which is synchronously controlled in vertical and horizontal directions scraping the liquid crystal substrates evenly on the surface of a petri dish. The thickness of the liquid crystal was profiled using laser diffraction technique and the homogeneity of the liquid crystal films produced was examined in a crossed-polarizing microscope. At an angular speed of 1500 rpm and under a shear stress of 1.46 ± 0.72 kPa, the squeegee coating was found producing liquid crystal films at a thickness of 132 ± 23 μm on the surface of petri dishes. With the application of this apparatus, evenly spread liquid crystal coatings with control thickness in petri dishes were consistently produced. This has overcome the major problem of manually coating the liquid crystal substrates using a cell scraper.