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Article
Publication date: 27 August 2019

Rahmat Zaki Auliya, Muhamad Ramdzan Buyong, Burhanuddin Yeop Majlis, Mohd. Farhanulhakim Mohd. Razip Wee and Poh Choon Ooi

The purpose of this paper is to propose an alternative approach to improve the performance of microelectromechanical systems (MEMSs) silicon (Si) condenser microphones in…

Abstract

Purpose

The purpose of this paper is to propose an alternative approach to improve the performance of microelectromechanical systems (MEMSs) silicon (Si) condenser microphones in terms of operating frequency and sensitivity through the introduction of a secondary material with a contrast of mechanical properties in the corrugated membrane.

Design/methodology/approach

Finite element method from COMSOL is used to analyze the MEMS microphones performance consisting of solid mechanic, electrostatic and thermoviscous acoustic interfaces. Hence, the simulated results could described the physical mechanism of the MEMS microphones, especially in the case of microphones with complex geometry. A 2-D model was used to simplify computation by applying axis symmetry condition.

Findings

The simulation results have suggested that the operating frequency range of the microphone could be extended to be operated beyond 20 kHz in the audible frequency range. The data showed that the frequency resonance of the microphone using a corrugated Si membrane with SiC as the embedded membrane is increased up to 70 kHz compared with 63 kHz for the plane Si membrane, whereas the microphone’s sensitivity is slightly decreased to −79 from −76 dB. Furthermore, the frequency resonance of a corrugated membrane microphone could be improved from 26 to 70 kHz by embedding the SiC material. Last, the sensitivity and frequency resonance value of the microphones could be modified by adjusting the height of the embedded material.

Originality/value

Based on these theoretical results, the proposed modification highlighted the advantages of simultaneous modifications of frequency and sensitivity that could extend the applications of sound and acoustic detections in the ultrasonic spectrum with an acceptable performance compared with the typical state-of-the-art Si condenser microphones.

Details

Microelectronics International, vol. 36 no. 4
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 19 March 2019

Muhammad Izzuddin Abd Samad, Muhamad Ramdzan Buyong, Shyong Siow Kim and Burhanuddin Yeop Majlis

The purpose of this paper is to use a particle velocity measurement technique on a tapered microelectrode device via changes of an applied voltage, which is an enhancement…

Abstract

Purpose

The purpose of this paper is to use a particle velocity measurement technique on a tapered microelectrode device via changes of an applied voltage, which is an enhancement of the electric field density in influencing the dipole moment particles. Polystyrene microbeads (PM) have used to determine the responses of the dielectrophoresis (DEP) voltage based on the particle velocity technique.

Design/methodology/approach

Analytical modelling was used to simulate the particles’ polarization and their velocity based on the Clausius–Mossotti Factor (CMF) equation. The electric field intensity and DEP forces were simulated through the COMSOL numerical study of the variation of applied voltages such as 5 V p-p, 7 V p-p and 10 V p-p. Experimentally, the particle velocity on a tapered DEP response was quantified via the particle travelling distance over a time interval through a high-speed camera adapted to a high-precision non-contact depth measuring microscope.

Findings

The result of the particle velocity was found to increase, and the applied voltage has enhanced the particle trajectory on the tapered microelectrode, which confirmed its dependency on the electric field intensity at the top and bottom edges of the electrode. A higher magnitude of particle levitation was recorded with the highest particle velocity of 11.19 ± 4.43 µm/s at 1 MHz on 10 V p-p, compared to the lowest particle velocity with 0.62 ± 0.11 µm/s at 10 kHz on 7 V p-p.

Practical implications

This research can be applied for high throughout sensitivity and selectivity of particle manipulation in isolating and concentrating biological fluid for biomedical implications.

Originality/value

The comprehensive manipulation method based on the changes of the electrical potential of the tapered electrode was able to quantify the magnitude of the particle trajectory in accordance with the strong electric field density.

Details

Microelectronics International, vol. 36 no. 2
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 23 September 2020

Muhamad Ramdzan Buyong, Farhad Larki, Muhamad Ikhmal Hakimi Zainal, Abdelaziz Yousif Ahmed Almahi, Ahmad Ghadafi Ismail, Azrul Azlan Hamzah, Aminuddin Ahmad Kayani Kayani, Céline Elie Caille and Burhanuddin Yeop Majlis

This paper aims to present the capacitance characterization of tapered dielectrophoresis (DEP) microelectrodes as micro-electro-mechanical system sensor and actuator…

Abstract

Purpose

This paper aims to present the capacitance characterization of tapered dielectrophoresis (DEP) microelectrodes as micro-electro-mechanical system sensor and actuator device. The application of DEP-on-a-chip (DOC) can be used to evaluate and correlate the capacitive sensing measurement at an actual position and end station of liquid suspended targeted particles by DEP force actuator manipulation.

Design/methodology/approach

The capability of both, sensing and manipulation was analysed based on capacitance changes corresponding to the particle positioning and stationing of the targeted particles at regions of interest. The mechanisms of DEP sensor and actuator, designed in DOC applications were energized by electric field of tapered DEP microelectrodes. The actual DEP forces behaviour has been also studied via quantitative analysis of capacitance measurement value and its correlation with qualitative analysis of positioning and stationing of targeted particles.

Findings

The significance of the present work is the ability of using tapered DEP microelectrodes in a closed mode system to simultaneously sense and vary the magnitude of manipulation.

Originality/value

The integration of DOC platform for contactless electrical-driven with selective detection and rapid manipulation can provide better efficiency in in situ selective biosensors or bio-detection and rapid bio-manipulation for DOC diagnostic and prognostic devices.

Details

Microelectronics International, vol. 37 no. 4
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 4 September 2020

Muhamad Ramdzan Buyong, Farhad Larki, Celine Elie Caille, Norazreen Abd Aziz, Ahamad Ghadafi Ismail, Azrul Azlan Hamzah and Burhanuddin Yeop Majlis

This paper aims to present the dielectrophoresis (DEP) force (FDEP), defined as microelectrofluidics mechanism capabilities in performing selective detection and rapid…

Abstract

Purpose

This paper aims to present the dielectrophoresis (DEP) force (FDEP), defined as microelectrofluidics mechanism capabilities in performing selective detection and rapid manipulation of blood components such as red blood cells (RBC) and platelets. The purpose of this investigation is to understand FDEP correlation to the variation of dynamic dielectric properties of cells under an applied voltage bias.

Design/methodology/approach

In this paper, tapered design DEP microelectrodes are used and explained. To perform the characterization and optimization by analysing the DEP polarization factor, the change in dynamic dielectric properties of blood components are observed according to the crossover frequency (fxo) and adjustment frequency (fadj) variation for selective detection and rapid manipulation.

Findings

Experimental observation of dynamic dielectric properties change shows clear correlation to DEP polarization factor when performing selective detection and rapid manipulation. These tapered DEP microelectrodes demonstrate an in situ DEP patterning efficiency more than 95%.

Research limitations/implications

The capabilities of tapered DEP microelectrode devices are introduced in this paper. However, they are not yet mature in medical research studies for various purposes such as identifying cells and bio-molecules for detection, isolation and manipulation application. This is because of biological property variations that require further DEP characterization and optimization.

Practical implications

The introduction of microelectrofluidics using DEP microelectrodes operate by selective detecting and rapid manipulating via lateral and vertical forces. This can be implemented on precision health-care development for lab-on-a-chip application in microfluidic diagnostic and prognostic devices.

Originality/value

This study introduces a new concept to understand the dynamic dielectric properties change. This is useful for rapid, label free and precise methods to conduct selective detection and rapid manipulation of mixtures of RBC and platelets. Further, potential applications that can be considered are for protein, toxin, cancer cell and bacteria detections and manipulation. Implementation of tapered DEP microelectrodes can be used based on the understanding of dynamic dielectric properties of polarization factor analysis.

Details

Microelectronics International, vol. 37 no. 4
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 3 May 2016

Arash Dehzangi, Farhad Larki, Sawal Hamid Md Ali, Sabar Derita Hutagalung, Md Shabiul Islam, Mohd Nizar Hamidon, Susthitha Menon, Azman Jalar, Jumiah Hassan and Burhanuddin Yeop Majlis

The purpose of this paper is to analyse the operation of p-type side gate junctionless silicon transistor (SGJLT) in accumulation region through experimental measurements…

Abstract

Purpose

The purpose of this paper is to analyse the operation of p-type side gate junctionless silicon transistor (SGJLT) in accumulation region through experimental measurements and 3-D TCAD simulation results. The variation of electric field components, carrier’s concentration and valence band edge energy towards the accumulation region is explored with the aim of finding the origin of SGJLT performance in the accumulation operational condition.

Design/methodology/approach

The device is fabricated by atomic force microscopy nanolithography on silicon-on-insulator wafer. The output and transfer characteristics of the device are obtained using 3-D Technology Computer Aided Design (TCAD) Sentaurus software and compared with experimental measurement results. The advantages of AFM nanolithography in contact mode and Silicon on Insulator (SOI) technology were implemented to fabricate a simple structure which exhibits the behaviour of field effect transistors. The device has 200-nm channel length, 100-nm gate gap and 4 μm for the distance between the source and drain contacts. The characteristics of the fabricated device were measured using an Agilent HP4156C semiconductor parameter analyzer (SPA). A 3-D TCAD Sentaurus tool is used as the simulation platform. The Boltzmann statistics is adopted because of the low doping concentration of the channel. Hydrodynamic model is taken to be as the main transport model for all simulations, and the quantum mechanical effects are ignored. A doping dependent Masetti mobility model was also included as well as an electric field dependent model with Shockley–Read–Hall (SRH) carrier recombination/generation.

Findings

We have obtained that the device is a normally on state device mainly because of the lack of work functional difference between the gate and the channel. Analysis of electric field components’ variation, carrier’s concentration and valence band edge energy reveals that increasing the negative gate voltage drives the device into accumulation region; however, it is unable to increase the drain current significantly. The positive slope of the hole quasi-Fermi level in the accumulation region presents mechanism of carriers’ movement from source to drain. The influence of electric field because of drain and gate voltage on charge distribution explains a low increasing of the drain current when the device operates in accumulation regime.

Originality/value

The proposed side gate junctionless transistors simplify the fabrication process, because of the lack of gate oxide and physical junctions, and implement the atomic force microscopy nanolithography for fabrication process. The optimized structure with lower gap between gate and channel and narrower channel would present the output characteristics near the ideal transistors for next generation of scaled-down devices in both accumulation and depletion region. The presented findings are verified through experimental measurements and simulation results.

Details

Microelectronics International, vol. 33 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 2 May 2017

Siti Kudnie Sahari, Muhammad Kashif, Norsuzailina Mohamed Sutan, Zaidi Embong, Nik Amni Fathi Nik Zaini Fathi, Azrul Azlan Hamzah, Rohana Sapawi, Burhanuddin Yeop Majlis and Ibrahim Ahmad

The quality of GeOx–Ge interface and the equivalent oxide thickness (EOT) are the main issues in fabricating high-k/Ge gate stack due to the low-k of GeOx interfacial…

Abstract

Purpose

The quality of GeOx–Ge interface and the equivalent oxide thickness (EOT) are the main issues in fabricating high-k/Ge gate stack due to the low-k of GeOx interfacial layer (IL). Therefore, a precise study of the formation of GeOx IL and its contribution to EOT is of utmost importance. In this study, the GeOx ILs were formed through post-oxidation annealing of sputtered Al2O3 on the Ge substrate. The purpose of this paper is to report on growth kinetics and composition of IL between Al2O3 and Ge for HCl- and HF-last Ge surface.

Design/methodology/approach

After wet chemical cleaning with HCl or HF, Al2O3 was grown onto the Ge surface by RF sputtering. Thickness and composition of IL formed after post-anneal deposition at 400°C in dry oxygen ambience were evaluated as a function of deposition time by FESEM and characterized by X-ray photoelectron spectroscopy, respectively.

Findings

It was observed that the composition and thickness of IL were dependent on the starting surface and an aluminum germinate-like composition was formed during RF sputtering for both HF- and HCl-last starting surface.

Originality/value

The novelty of this work is to investigate the starting surface of Ge to IL growth between Al2O3/Ge that will lead to the improvement in Ge metal insulator field effect transistors (MISFETs) application.

Details

Microelectronics International, vol. 34 no. 2
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 May 2020

Norliza Katuk, Ku Ruhana Ku-Mahamud, Kalsom Kayat, Mohd. Noor Abdul Hamid, Nur Haryani Zakaria and Ayi Purbasari

Halal tourism is a subset of tourism activities geared towards Muslim which are aligned with the Islamic principles. As a response to this, many food operators have…

Abstract

Purpose

Halal tourism is a subset of tourism activities geared towards Muslim which are aligned with the Islamic principles. As a response to this, many food operators have realised the importance of having a halal certification to establish a better market position. In the context of Indonesia, it is yet to be known what attitudes the food operators have towards halal certification and what attributes characterised those who have obtained the certification. Therefore, this study aims to examine the attributes of food operators and their attitudes towards halal certification in Indonesia.

Design/methodology/approach

A survey and structured interview were conducted on 298 food operators in Bandung, a city in Indonesia, between August and December 2018. Seven hypotheses were proposed and tested to evaluate the association between halal certification and food operators’ attributes and their attitudes towards it.

Findings

The results of the study suggested that food operators who had halal certification can be characterised by the number of branches the businesses have, the knowledge of halal tourism and knowledge on the market segment. However, the age of their business was found not related to halal certification. In terms of attitudes, the study found that performance beliefs, intention to apply and target market segment had associated with halal certification.

Practical implications

The outcomes of the study could provide information to entities and agencies involved in the tourism industry that consider targeting Muslim travellers as their market segment. Halal certification could be an approach to facilitate tourism marketing and consequently increase the performance of food-related business sectors.

Originality/value

This study provides evidence that could lead to a better understanding of the attributes of food operators and their attitudes towards halal certification in the context of Indonesia’s tourism industry.

Details

Journal of Islamic Marketing, vol. 12 no. 5
Type: Research Article
ISSN: 1759-0833

Keywords

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