Nurul Amziah Md Yunus

Continuous separation of colloidal particles using dielectrophoresis.

Dielectrophoresis is the movement of particles in nonuniform electric fields and has been of interest for application to manipulation and separation at and below the microscale. This technique has the advantages of being noninvasive, nondestructive, and noncontact, with the movement of particle achieved by means of electric fields generated by miniaturized electrodes and microfluidic systems. Although the majority of applications have been above the microscale, there is increasing interest in application to colloidal particles around a micron and smaller. This paper begins with a review of colloidal and nanoscale dielectrophoresis with specific attention paid to separation applications. An innovative design of integrated microelectrode array and its application to flow‐through, continuous separation of colloidal particles is then presented. The details of the angled chevron microelectrode array and the test microfluidic system are then discussed. The variation in device operation with applied signal voltage is presented and discussed in terms of separation efficiency, demonstrating 99.9% separation of a mixture of colloidal latex spheres.

Design and simulation of high performance RF MEMS series switch

This paper describes the process, design the switch structures and simulate certain parameters to develop a high performance RF MEMS switch with low voltage, low loss and high isolation. The RF MEMS switches are series switches type and are designed using physical level approach by using 3D MEMS commercial software package, Intellisuite. These switch structures are first designed using 2D layout which then is converted to 3D model to simulate the actuation voltage. The optimization analysis also simulated to obtain the low voltage with the adjustment of air gap distance and top electrode design structure. The RF performance is then simulated using the electromagnetic analyzer, Emag to calculate the insertion loss and isolation value during the ON and OFF state conditions. Several designs are proposed and the best performance switch gives a low voltage actuation of 7V with low loss of0.083 dB and high isolation of −78.3 dB at 1.2 GHz.

Numerical simulation of CIGS thin film solar cells using SCAPS-1D

The performance of copper indium gallium diselenide (CIGS) thin film solar cell has been numerically simulated with different buffer and absorber layers thickness. The cell structure based on CIGS compound semiconductor as the absorber layer, indium sulfide as a buffer layer, un-doped (i) and n-doped zinc oxide as a window layer has been simulated using the simulation program called SCAPS-1D. This study aimed to find the optimum thickness of buffer and absorber layer for a CIGS thin film solar cells with indium sulfide buffer layer. It is found that the optimum thickness of the buffer layer is from 40nm to 50nm and for the absorber layer is in the range of 2000nm to 3000nm.

A review on high-resolution CMOS delay lines: towards sub-picosecond jitter performance

A review on CMOS delay lines with a focus on the most frequently used techniques for high-resolution delay step is presented. The primary types, specifications, delay circuits, and operating principles are presented. The delay circuits reported in this paper are used for delaying digital inputs and clock signals. The most common analog and digitally-controlled delay elements topologies are presented, focusing on the main delay-tuning strategies. IC variables, namely, process, supply voltage, temperature, and noise sources that affect delay resolution through timing jitter are discussed. The design specifications of these delay elements are also discussed and compared for the common delay line circuits. As a result, the main findings of this paper are highlighting and discussing the followings: the most efficient high-resolution delay line techniques, the trade-off challenge found between CMOS delay lines designed using either analog or digitally-controlled delay elements, the trade-off challenge between delay resolution and delay range and the proposed solutions for this challenge, and how CMOS technology scaling can affect the performance of CMOS delay lines. Moreover, the current trends and efforts used in order to generate output delayed signal with low jitter in the sub-picosecond range are presented.

Detection of Aeromonas hydrophila Using Fiber Optic Microchannel Sensor

This research focuses on the detection of Aeromonas hydrophila using fiber optic microchannel biosensor. Microchannel was fabricated by photolithography method. The fiber optic was chosen as signal transmitting medium and light absorption characteristic of different microorganisms was investigated for possible detection. Experimental results showed that Aeromonas hydrophila can be detected at the region of UV-Vis spectra between 352 nm and 354 nm which was comparable to measurement provided by UV spectrophotometer and also theoretical calculation by Beer-Lambert Absorption Law. The entire detection can be done in less than 10 minutes using a total volume of 3 μL only. This result promises good potential of this fiber optic microchannel sensor as a reliable, portable, and disposable sensor.

Intelligent massage chair based on blood pressure and heart rate

Massage is one of the effective techniques used to relieve pain, reduce stress, and increase relaxation. Nowadays, massage methods have varied to an easier way by electronic massage chair massage which is able to control the massage mode according to specifications. Commercial massage chair can only be used on normal healthy people with no health complication, such as diabetes, heart problem or blood pressure problem. The purpose of this study is to develop a system of more advanced massage chair where it can have an impact on user health based on blood pressure and heart rate. The proposed massage chair equipped with blood pressure and heart rate sensors, where the therapy will automatically configured according to individuals blood pressure and heart rate readings. The proposed control system developed using the artificial intelligent of fuzzy logic for data classification. The complete model of this massage control system is then developed using SIMULINK software to simulate the whole system operation and verify the function as programmed. Upon the success of the investigation, the findings will be useful for rapid advances in the existing technology.

Design of a microstrip SPDT PIN diode switch

PIN diode microwave switch is designed using microwave harmonica and fabricated using PIN diode MA 47110, and realized on the microstrip. The switch is called single pole double throw, SPDT, switch and operating at 4 GHz.

Numerical Analysis of In2S3 Layer Thickness, Band Gap and Doping Density for Effective Performance of a CIGS Solar Cell Using SCAPS

The effect of indium sulfide buffer layer’s geometrical and electro-optical properties on the Copper–Indium–Gallium–diSelenide solar cell performance using numerical simulation is investigated. The numerical simulation software used is a solar cell capacitance simulator in (SCAPS). The innermost impacts of buffer layer thickness, band gap, and doping density on the cells output parameters such as open circuit voltage, short circuit current density, fill factor, and the efficiency were extensively simulated. The results show that the cell efficiency, which was innovatively illustrated as a two-dimensional contour plot function, depends on the buffer layer electron affinity and doping density by keeping all the other parameters at a steady state. The analysis, which was made from this numerical simulation, has revealed that the optimum electron affinity is to be 4.25 ± 0.2 eV and donor density of the buffer layer is over

Dual control Direct Digital Synthesizer (DCDDS) for electronic testing and experimental work

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