Jumril Yunas
Universiti Kebangsaan Malaysia

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Design and Fabrication of Compact MEMS Electromagnetic Micro-Actuator with Planar Micro-Coil Based on PCB Roer Eka Pawinanto; Jumril Yunas; Burhanuddin Majlis; Azrul Hamzah
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 14, No 3: September 2016
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v14i3.3998

Abstract

This paper reports a compact design of electromagnetically driven MEMS micro-actuator utilizing planar electromagnetic coil on PCB (Printed Circuit Board). The micro-actuator device consists of an NdFeB permanent magnet, thin silicon membrane and planar micro-coil which fabricated using simple standard MEMS techniques with additional bonding step. Two planar coils designs including planar parallel and spiral coil structure with various coil geometry are chosen for the study. Analysis of the device involves the investigation of electromagnetic and mechanical properties using finite element analysis (FEA), the measurement of the membrane deflection and functionality test. The measurement results show that the thin silicon membrane is able to deform as much as 12.87 µm using planar spiral micro-coil. Reasonable match between simulation and measurement of about 82.5% has been revealed. The dynamic response test on actuator driven by parallel planar coil shows that silicon membrane effectively deformed in 40 s for an input electrical power of only 150 mW. It is also concluded that planar parallel coil is considered for the simple structure and easy fabrication of the actuator system. This study will provide important parameters for the development of compact and simple electromagnetic micro-actuator system for fluidic injection system in lab-on-chip.
Optimization of KOH etching process for MEMS square diaphragm using response surface method Norliana Yusof; Badariah Bais; Burhanuddin Yeop Majlis; Norhayati Soin; Jumril Yunas
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 1: July 2019
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v15.i1.pp113-121

Abstract

KOH wet etching is widely used in realizing MEMS diaphragm due to its low cost, safe and easy handling. However, wet etching process parameters need to be studied thoroughly in order to realize the desired shape and size of MEMS devices. This paper presents the numerical study and optimization of KOH etching process parameters using the response surface method (RSM). Face central composite design (FCC) of RSM was employed as the experimental design to analyze the result and generate a mathematical prediction model. From the analysis, the temperature was identified as the most significant process parameter that affects the etching rate, thus affecting the thickness and size of the diaphragm. The results of RSM prediction for optimization were applied in this study. Particularly, 45% of KOH concentration, temperature of 80°C, 1735 µm2 of mask size, and 7.2 hours of etching time were implemented to obtain a square MEMS diaphragm with thickness of 120 µm and size of 1200 µm2. The results of RSM based optimization method for KOH wet etching offers a quick and effective method for realizing a desired MEMS device.
Biomass-Based Supercapacitors Electrodes for Electrical Energy Storage Systems Activated Using Chemical Activation Method: A Literature Review and Bibliometric Analysis Ida Hamidah; Ramdhani Ramdhani; Apri Wiyono; Budi Mulyanti; Roer Eka Pawinanto; Lilik Hasanah; Markus Diantoro; Brian Yuliarto; Jumril Yunas; Andrivo Rusydi
Indonesian Journal of Science and Technology Vol 8, No 3 (2023): (ONLINE FIRST) IJOST: December 2023
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v8i3.60688

Abstract

Currently, carbon derived from biomass waste or residues is being intensively utilized as electrodes due to its excellent electrical properties, including high conductivity, appropriate porosity, and a specific surface area suitable for supercapacitor applications. Despite its advantages, the performance of supercapacitors made from biomass-derived carbon is insufficient for engineering applications because of the challenges in obtaining the mesoporous structure of activated carbon (AC). Therefore, this study highlights the potential of biomass-based carbon as the electrodes of a highly efficient supercapacitor, which can facilitate highly efficient current transport in energy storage systems. It comprehensively discusses various biomass material sources and activation methods to produce carbon, with a focus on the physical and electrical properties. Initially, the study discusses carbon activation methods and mechanisms to understand why activating agents and electrolyte solutions have a high specific surface area and specific capacitance. It then concentrates on the chemical activation method and its importance in making AC useful as an efficient electrode. Finally, in this study, various biomass sources were discussed to highlight the performance of supercapacitors electrodes originating from agricultural and wood residues relating to the specific capacitance and capacitance retention. Based on the obtained results, it is concluded that biomass-based carbon materials could be the most advantageous platform material for energy conversion and storage.