Asral Bahari Jambek
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Preferred name
Asral Bahari Jambek
Official Name
Asral , Bahari Jambek
Alternative Name
Jambek, Asral Bahari
Bahari Jambek, Asral
Jambek, Asral Bin Bahari
Main Affiliation
Scopus Author ID
57195722408
Researcher ID
AAG-2050-2021

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Design of a Huffman data encoder architecture

2018-10 , Nor Alina Khairi , Asral Bahari Jambek , Nor Asilah Khairi

Wireless sensor networks (WSNs) are important in today’s technology for helping to monitor our environment. WSNs are widely used in military, medical and industrial environments. It is capable of monitoring, collecting and transmitting data to a primary server wirelessly. Wireless sensor nodes are powered by a limited energy supply such as a small battery or an energy harvester that generally produces a small amount of energy. To extend the lifetime of the device, energy consumption must be reduced. Data transmission is known to consume the largest percentage of energy in a sensor node. One method for reducing energy is by compressing the data prior to transmitting it. This study analyses the performance of the Huffman architecture in terms of compressing data that are commonly used in wireless sensor nodes. The primary module in the architecture comprises a data retriever, frequency calculator, probability calculator, Huffman tree generator and Huffman code generator. From the experimental results, the Huffman circuit architecture simulation consumed 51394 clock cycles to completely compress 366 data samples, using 3.729mW of power consumption. Based on a 20MHz clock frequency, this is equivalent to 9.5824μJ of energy consumption. Based on our analyses, the Huffman tree generator consumed the most power at 1.184mW, equivalent to 31.75% of overall power consumption.

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Development of voltage amplifier electronic reader using NodeMCU

2020-11-02 , Muhammad Nur Aiman Uda , Muhammad Nur Aiman Uda , Uda Hashim , Asral Bahari Jambek

Generally, two electrode based amperometric biosensors show extremely low current signal output around pico ampere (pA) to micro ampere (μA) range. This paper describes the development of electronic reader to capture and amplify four different range of current as mili, micro, nano and pico ampere and convert it to detectable voltage range as an output signal to the microcontroller. The MAX4238 op-amp IC was used to amplify micro voltage to mili voltage. NodeMCU was act as the process and control circuit to read the output voltage from the amplifier circuit. The entire system is comprised of a voltage amplifier circuit, filter circuit, microcontroller and power supply unit. The range of the current measurement of the system was from 1 pA to 650mA. The amplifier operation was measured with a high impedance current source and has been compared with the theoretical measurement. The Design Spark PCB software was used to design the voltage amplifier circuit. Arduino software was used to create a programming code to upload in NodeMCU microcontroller.

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Development of Internet of Things (IOT) Based Electronic Reader for Medical Diagnostic System

2020-03-18 , Muhammad Nur Afnan Uda , Asral Bahari Jambek , Uda Hashim , Muhammad Nur Aiman Uda , Bahrin M.A.F.

This paper is about an experiment for performing foodborne pathogens electronic reader using wireless sensing Internet of Thing (IoT). There are limited number of electronic readers for biosensors application with wireless internet connection. This research is to overcome the problem of commercial available electronic reader based on biosensor application method that only can be perform in offline or standalone device. This paper shows a complete system on how the data from electronic reader can be collected, easily understand by user and transfer data through the wireless internet connection via platform of IoT. There are three stages that is coding modification, android application development and transmit data to cloud storage. The NodeMCU microcontroller was used as a transfer medium for transfer data to internet. The Android Studio software was used for mobile application development. While, Arduino software was used to create a programming code to upload in NodeMCU microcontroller.

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Electrical DNA Biosensor Using Aluminium Interdigitated Electrode for Salmonella Detection

2020-03-18 , Muhammad Nur Afnan Uda , Asral Bahari Jambek , Uda Hashim , Muhammad Nur Aiman Uda

Nowadays there are many alternative methods that have been discovered and developed for the rapid detection of foodborne pathogens that can cause food poisoning. Unfortunately, majority of them still requires improvement in sensitivity and selectivity issues to be of any practical use daily. In this research, biosensors was prepared from 5 m gap Aluminium interdigitated electrode (Al IDE) to detect Salmonella enterica typhi (S. typhi). The IDE sensors in the biosensor field is extremely interest in these days due to the high number of finger electrodes as comb structure which can gain high sensitivity through electrical measurements. S. typhi is a serious food borne pathogen, makes typhoid disease which causes many deaths annually in worldwide. Functionalization steps of the Al IDE to create biosensor was based on silanization by APTES, immobilization with carboxylic functionalized S. typhi ssDNA probes and blocking agent with tween-20 were the major functionalization steps. The functionalized steps were electrically characterized using current voltage measurements. The selectivity measurement was performed with specific target was identified electrically using complementary, non-complementary and single base mismatch ssDNA target.

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Design 5.0 µm Gap Aluminium Interdigitated Electrode for Sensitive pH Detection

2020-07-09 , Muhammad Nur Afnan Uda , Asral Bahari Jambek , Uda Hashim , Muhammad Nur Aiman Uda , Nor Azizah Parmin , Bakar A.H.A. , Anuar A. , Bakar M.A.A. , Sulaiman M.K.

The aim of the research study to design high sensitive biosensor for medical applications. IDE pattern was designed using AutoCAD software with 5 µm ginger gap. The fabrication process was done using a conventional photolithography process and standard CMOS process. The fabricated electrode was physically characterized using a low power microscope (LPM) and a high power microscope (HPM). The electrically validated through I-V measurements and chemically tested with different pH buffer solutions. Al IDE was well fabricated with 0.1 µm tolerance between the design mask and fabricated IDEs. Electrical measurements confirmed that IDE was well fabricated without any shortage and results of similar IDE samples were confirmed that the repeatability of the device. The extremely small current variations in nano ampere range were quantitatively detected using an extra small volume of 2 µl for different pH buffer solutions. It is confirmed that IDEs are sensitive in both alkali and hydroxyl ions medium.

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Nano-micro-mili Current to Mili Voltage Amplifier for Amperometric Electrical Biosensors

2020-03-18 , Muhammad Nur Afnan Uda , Parmin N.A. , Asral Bahari Jambek , Uda Hashim , Muhammad Nur Aiman Uda , Shaharuddin S.N.A. , Adam H.

Amplification of nano and mircoampere electrical signal to the detectable range is essential in the biosensor field. This research is mainly focused on design an amplifier circuit to capture and amplify three different range of current as nano, micro and mili ampere and convert it to detectable voltage range as an output signal to the processing circuit. The Proteus 8 Pro software was used to design, simulate and calibrate the amplifier circuit. Firstly, current input as mili, micro and nano current were flown through 0.1 m, 10 and 10 K resistors, respectively to convert different current inputs to the similar range in micro voltage. The MAX 4238 opamp IC was used to amplify micro voltage to mili voltage. LM 358 dual operational amplifier was used to supply virtual ground to MAX 4238 amplifier. The amplified output voltage of three different current inputs as nano, micro and mili were nearly equal to theoretical outputs.

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Design and analysis of a two-stage OTA for sensor interface circuit

2014 , Siti Nur Syuhadah Baharudin , Asral Bahari Jambek , Rizalafande Che Ismail

This paper discusses the design of an operational transconductance amplifier (OTA) circuit foruse in a capacitive sensor interface circuit. The OTA converts a differential voltage input into the current as part of a switched capacitor integrator module. In this paper, a two-stage OTA is proposed which has high gain, high output swing and low noise. The circuit wasimplemented using 0.13μm Silterra CMOS technology and simulated using the Mentor Graphic Design Architect software package. The results show that the OTA is able to achieve74dB gain and 20KHz bandwidth when operated using a 2.5V power supply, with a total power consumption of 1.3mW. © 2014 IEEE.

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Evaluation and Optimization of Genomic DNA Extraction from Food Sample for Microfluidic Purpose

2020-03-18 , Muhammad Nur Afnan Uda , Nor Azizah Parmin , Asral Bahari Jambek , Uda Hashim , Muhammad Nur Aiman Uda , Shaharuddin S.N.A.

Contamination of various food samples became one of the critical issues in food pathogen infection. Food pathogen can be detected by using digital polymerase chain reaction (PCR) and sequencing. These methods were reliable but consuming and take a longer time for detection. The present work describes the innovation to develop a technology to extract double-stranded deoxyribonucleic acid (dsDNA) from food samples and then denatured dsDNA into and single-strand DNA (ssDNA) for further use on the chip using microfluidic device. Microfluidic device is a lab-on-chip device that consist of microfluidic channels that provide paths for biomolecules to flow to individual point of care. DNA extraction is the process by which DNA is separated from proteins, membranes, and other cellular material contained in the cell from which it is recovered. Lysis solution is used in the process of extraction the DNA to break up the cells containing DNA from protein and other cellular materials. This extraction firstly be done in the most labour-intensive in obtaining the DNA biomolecules. Extraction methods may require an overnight incubation, may be a protocol that can be completed in minutes or a couple of hours by using a commercial kit. The disadvantages of the laboratory and commercial kit is due to time-consuming, poor cost-effectiveness, the need to use big laboratory and a complicated process which need an expertise to conduct the experiment and interpret the data. This research is proposed to design and fabricate a microfluidic device that has DNA extraction capabilities. In this research DNA extraction using a commercial kit will be used as a comparison for the quality of the result. The microfluidic device can be used in health care delivery system and will help the doctors in diagnostic process to identify disease of a patient rapidly. Other than that, the output extracted from microfluidic device will be used for DNA probe target interaction for diagnostic kit. The major advantage of microfluidic device is that it consumes less time compared to the conventional chemical methods.

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Aluminium interdigitated electrode with 5.0 μm gap for electrolytic scooting

2024-06 , Uda Hashim , Muhammad Nur Aiman Uda , Tijjani Adam , Asral Bahari Jambek , Ismail Saad , Nor Azizah Parmin , Shahidah Arina Shamsuddin , Nursakinah Abdul Karim , G. Yashni , Nur Hulwani Ibrahim , N. Parimon , M. F. H. Rani

The goal of the research project is to design, fabricate, and characterize an extremely sensitive biosensor for use in healthcare. Using AutoCAD software, a novel IDE pattern with a 5 μm finger gap was created. Conventional photolithography and regular CMOS technology were used in the fabrication process. A 3D nano profiler, scanning electron microscopy (SEM), high-power microscopy (HPM), and low-power microscopy (LPM) were used to physically characterize the manufactured IDE. Chemical testing was done using several pH buffer solutions, and electrical validation was performed using I-V measurements. The Al IDE was produced, with a tolerance of 0.1 μm between the fabricated IDEs and the design mask. Electrical measurements verified the flawless fabrication of the IDE, and the device's repeatability was validated by the outcomes of comparable IDE samples. For each pH buffer solution, a modest additional volume of 2 μl was used to quantitatively detect slight current fluctuations in the microampere range. Through pH calibration for advanced applications in the realm of chemical sensors using an amperometric method, this research study has verified the chemical behavior of the IDE.

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Aluminium Interdigitated Electrode Based Biosensor for Specific ssDNA Target Listeria Detection

2020-03-18 , Muhammad Nur Afnan Uda , Asral Bahari Jambek , Uda Hashim , Muhammad Nur Aiman Uda , Bahrin M.A.F.

Nowadays interdigitated electrode (IDE) based sensor have stimulated increasing interest in the application of biosensor filed. A large number of finger electrodes as comb structure gain high sensitivity through electrical measurements. In this paper, we have investigated Listeria bacteria detection through the electrical based IDE. Listeria monocytogenes is a food borne pathogen-based bacterium that can cause dangerous disease to human, some infection may result in death. The AutoCAD software was used to design the chrome mask of IDE sensor and the fabrication process was done using conventional photolithography method. The fabricated Al IDE morphologically analyzed using a low power microscope (LPM), a high-power microscope (HPM) and 3D profiler. Functionalization step of the Al IDE, silanization process was done using (3-Aminopropyl) triethoxysilane (APTES), immobilization process was done using carboxylic probe Listeria and Tween-20 as a blocking agent for nonspecific binding on the non-immobilized area of the biosensor surface. The biosensor was validated with complementary, non-complementary and single base mismatch ssDNA targets. Different concentration of complementary ssDNA target from 1 fM to 1 M was done for the sensitivity detection.

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