A complete system modelling of Piezoelectric Energy Harvester (PEH) with Silicon Carbide (SiC) Used as cantilever base

Silicon carbide (SiC) is a material that possesses hardness and robustness to operate under high temperature condition. This work is a pilot in exploring the feasibility of cubic piezo element on the SiC wafer with integrated proof mass as horizontal cantilever with perpendicular displacement with respect to the normal plane. With the advance of electronic circuitry, the power consumption is reduced to nano-watts. Therefore, harvesting ambient energy and converting into electrical energy through piezoelectric material will be useful for powering low power devices. Resonance is a property which able to optimize the generated output power by tuning the proof masses. The damping ratio is a considerable parameter for optimization. From analytical study, small damping ratio will enhance the output power of the piezoelectric energy harvester (PEH). This paper will present mathematical modelling approach, simulation verification and the conditional circuit named versatile precision full wave rectifier

Reliability of electrocardiogram signals during feature extraction stage for smart textile shirts

Wearable smart textiles have garnered significant interest due to their high flexibility, reusability, convenience and ability to work on home-based, real-life and real-time monitoring. Wearable smart textiles are shirts with inbuilt textile sensors that enable electrocardiogram (ECG) data to be collected more comfortably and smoothly outside the laboratory and clinical environment for a continuous and longer duration for ECG data collection. However, the existing ECG wearable smart textile main challenge is maintaining the quality and reliability of data across multiple wearable smart textile shirts. Therefore, this research analyses the capability of ECG morphology during Feature Extraction stages for different wearable smart textile shirts. This paper reports the experiment conducted on eleven healthy volunteers, either wearing the Hexoskin smart shirt or the HeartIn Fit shirt or both. ECG data were recorded while they are doing normal daily routine activities for at least 45 minutes. The study demonstrates a significant possibility of reliability in Feature Extraction stages at different time instances among subject and wearable smart textiles shirts. With R peaks average between 0.543 to 1.194 mV and R-R interval average between 0.625 to 0.799 seconds, the study concludes that both wearable smart textiles do not significantly differ in Feature Extraction stages. Thus, both wearable smart textiles gave a significant result, although both are affected by their wearer's motion artefacts during the shifting of body postures and the wearer's body physical states. Furthermore, the ECG morphology in this study has yielded a promising result in real life and as on-the-go ECG smart textile biometric readiness for future explorations

The response of EEG signal on Brain Relaxation Meditation using different type of zikr

Depression and stress are increasingly prevalent in today’s society, owing to people's hectic, competitive, and demanding lifestyles. These illnesses had become very common, particularly among young and middle-aged people, and suicidal ideation had been identified as one of the leading causes of death by the World Health Organization (WHO). Nature sound (sound of downpours or beach) has been linked to depression and anxiety in neurology research, and it has been shown to be an alternative to alleviate anxiety. The electroencephalogram (EEG) waveform has been discovered to possess the potential in identifying information from the brain signal as well as data from the past via Bluetooth communication. The waveform use in the study are the result of a few experiments. In this study, EEG data were collected from eight subjects, four males and four females, in between the age of 20 to 30 years old and in good health, using the BrainLink device. The participants were asked to listen to two playlists of zikr, Allah, Ya Allah, and SubhanAllah, during the experiments. To smooth the signal, the Butterworth filter was used. Later, the extracted features were Alpha, Beta, and Delta waves, which were segmented based on the filtered signal. To complete the decision-making stage, the average value of amplitude differences and the p-value test were performed in the final phase. Based on the results of the experiments, it is clear that zikr is dominant in Delta wave. In terms of data hypothesis analysis, the results of both experiment were differentiated to determine which brain signal was dominant, and pvalue testing was performed. Furthermore, this research is an alternative to current methods because it suggest that zikr has the tendency to alter a person's brain state to be either in a relaxed or calm mode regardless of the type of zikr recitation. As an outcome, the study recommends the relationship of the reaction of EEG signal on brain relaxation with different types of zikr in order to facilitate stress and anxiety patients to achieve relax or calm condition

Development of five port reflectometer for reflection based sensing system

Five-Port Reflectometer is a microwave passivedevice where it implements the six-port algorithm to measure the complex reflection coefficient of material under test (MUT) through reflection on interface between MUT and microwave sensor. Initially, the Six-Port Reflectometer (SPR) was introduced by Engen in 1977 and major component used insix-port technique was designed in many types. When Riblet and Hanssonproposed ring junction with 5 ports only on 1981. Six ports ring junction has been reduced to five ports. In this paper, a dual frequency five ports ring junction circuit was designed, simulated and fabricated for reflection based sensing system. The fabricated five port ring junction is operating at frequencies of 0.64 GHz and 2.42 GHz. The measured result had good agreement with the simulated results for dual frequencies in terms of magnitude and phase

Image Enhancement Techniques Using Local, Global, Bright, Dark and Partial Contrast Stretching For Acute Leukemia Images

Leukaemia is a malignant disease (cancer) that affects people in any age either they are children or adults over 50 years old.Nowadays, there are screening system guidelines for leukaemia patients.The screening result from looking at a sample of patient blood, can determine the abnormal levels of white blood cells, which may suggest leukaemia for further diagnostic stage. Therefore, medical professional using medical images to diagnose leukemia. However, there are blurness and effects of unwanted noise on blood leukaemia images that sometimes result in false diagnosis.Thus image pre-processing such as image enhancement techniques are needed to improve this situation.This study proposes several contrast enhancement techniques which are local contrast stretching, global contrast stretching, partial contrast stretching, bright and dark contrast stretching.All techniques are applied on the leukaemia images.The comparison for all the proposed image enhancement techniques was carried out to find the best technique to enhance the acute leukaemia images. The results show that the partial contrast stretching is the best technique that helps to improve the image quality

Application of sol gel technique for glucose oxidase immobilization in biosensor application

A sol gel based biosensor using 3-glycidoxypropyl dimethylethoxysilane, as a silane agent was developed as a novel method for biosensor enzyme immobilization. The key materials applied were tetra methyl orthosilicate (TMOS), and the cross link agent, 3-Glycidoxypropyl dimethylethoxysilane, (GDP). Three compositions with different amount of GDP and glucose oxidase were experimented with the amount of TMOS was kept constant. The first coating consisted of 2mg of glucose oxidase and 20µl of GDP. The second trial involved higher GDP composition which is 100µl. The final trial applied higher content of glucose oxidase which is 12 mg with 20µl of GDP. The result showed that sensors with high composition of crosslink agent coating was capable to exhibit reliable glucose detection. The crosslink agent insufficiency in the first composition failed to provide good attachment for the enzyme on the electrode. Thus, the test was halted after few readings due to the inability of the sensor to detect glucose increment. For the high amount glucose oxidase composition, failure happened due to the deficiency of GDP to retain the enzyme thus contributed to the glucose oxidase leaching. We conclude that adequate amount of crosslink agent is vital for a sol gel based biosensor to function successfully

Simulation of Low-Frequency Sonophoretic Piezoelectric Transducer Applied over Human Skin

Sonophoresis is the process that involves the passage of drug molecules through the skin under ultrasonic stimulation. Drugs with a molecular weight greater than 500 daltons require some kind of stimulus to catalyze their penetration into the skin. Low-frequency sonophoresis, i.e., applying low-frequency (20–100 kHz) ultrasonic waves, is one of the active methods of stimulation used in transdermal drug delivery. The aim of this research is to explore the possibility of achieving high enough acoustic pressures inside human skin using a single-element piezoelectric transducer required to realize the transdermal delivery of drugs with a high molecular weight. Therefore, this paper presents a design and simulation of a single-element transducer to find voltage versus sound pressure levels (SPLs), as well as frequency response curves for low-frequency sonophoresis on human skin. A piezoelectric transducer composed of PZT-5H placed over human skin was simulated by combining the pressure acoustic module, solid mechanics, and electrostatic modules of the simulation tool. The presented simulation applies sinusoidal excitation to a PZT-5H-based transducer. The peak voltage and the frequency of the input are varied to study the resulting variations in acoustic pressure and SPL inside the human skin. Measurements of acoustic pressure are taken 0.1 mm deep into the human skin. The peak acoustic pressure increases linearly from 0.072 Pa to 0.72 Pa as the peak applied voltage increases from 1 mV to 10 mV. The peak acoustic pressure increases exponentially from 0.2 mPa to 5 mPa as the frequency varies from 20 kHz to 100 kHz for a constant peak voltage of 1 mV. The SPL achieved at 880 kHz is 186 dB, which is suitable for drug delivery in some areas of medicine, such as ophthalmology

Synthesis methods of doped hydroxyapatite: a brief review

Hydroxyapatite (HA) has drawn great attention to biomedical applications due to their bone mineral similarity, strong bioactivity, biocompatibility and osteoconductive. Despite the fact that HA has many advantages, several properties are still lacking, emphasising the crucial need for ion doping/substitution. Many attempts have been made to incorporate ions into HA structure to increase their physical, chemical, and biological properties. With such a diverse range of methods available for the synthesis of doped HA, this article discussed the importance of doping for HA and summarizes four common techniques used to prepare doped hydroxyapatites which include precipitation, hydrothermal, sol-gel and mechanochemical metho

Cooling Performance of Thermoelectric Cooling (TEC) and Applications: A review

Thermoelectric cooling (TEC) is a new attractive method that is can be used as a temperature controller. Thermoelectric module (TEM) is a device that environmentally friendly utilizing for cooling and heating application such as heat pump and power generation. Therefore, the understanding of relation between electrical conductivity and heat conductivity of the TEC material is essentially to improve the coefficient of performance (COP) efficiency. The figure of merit is addressed by focusing the best material in TEC with different cooling material. The critical finding of TEC for this review paper is the higher the electrical conductivity and the lower thermal conductivity, the maximum the COP. Finally, the possiblity of the TEC application is reviewed according to the advantages of TEC such as high reliability, less maintenance and compact size that commercially found in large range of thermoelectric cooling system.

Cooling Performance of Thermoelectric Cooling (TEC) and Applications: A review

Thermoelectric cooling (TEC) is a new attractive method that is can be used as a temperature controller. Thermoelectric module (TEM) is a device that environmentally friendly utilizing for cooling and heating application such as heat pump and power generation. Therefore, the understanding of relation between electrical conductivity and heat conductivity of the TEC material is essentially to improve the coefficient of performance (COP) efficiency. The figure of merit is addressed by focusing the best material in TEC with different cooling material. The critical finding of TEC for this review paper is the higher the electrical conductivity and the lower thermal conductivity, the maximum the COP. Finally, the possiblity of the TEC application is reviewed according to the advantages of TEC such as high reliability, less maintenance and compact size that commercially found in large range of thermoelectric cooling system.