International UNIMAS STEM EnCon2018 | 12 - 14 September 2018| Kuching, Sarawak

Keynote Speaker 1 : Professor Dato’ Dr. Burhanuddin bin Haji Yeop

Professor Dato’ Dr. Burhanuddin bin Haji Yeop
MEMS based Chemical Sensors for Biomedical Applications
In a chemical sensing system for biomedical applications, the system usually consist of a chemical sensing unit [1], microfluidic [2] and pumping system [3], microgenerator unit to power up the sensors [4], and an energy storage device [5].
CuO and ZnO nanowires could be fabricated into a highly sensitive gas and chemical sensors for biomedical applications [1]. Metal oxides nanostructures are important materials involving in the development of gas detection systems, but most of them only working at elevated temperature. A diode based structure of p-type copper oxide (CuO) and n-type zinc oxide (ZnO) nanowires (NWs) on silicon, which posses rectifying I-V characteristic, was fabricated to overcome this drawback. Chemical sensing characteristics of CuO NWs and ZnO NWs with and without diode structure have been examined by measuring the resistance change towards 0.5% methanol vapour at room temperature. The diode based structures showed significant improvement in sensing behaviours. The implementation of CuO NWs and ZnO NWs with diode based structures showed great enhancement in terms of sensitivity, reliability and recovery rate. Elements to be detected are guided into microfluidic channels using MEMS micropumps [2,3]. The micro chamber and the fluidic channel were fabricated using standard photolithography and soft lithography process. Conventional method by pouring PDMS on a silicon wafer and peeling after curing in soft lithography produces unspecific layer thickness [2]. In the micropump, planar valveless design is used [3]. The technique utilizes MEMS fabrication methods by using a double sided etch. A planar diffuser and a nozzle element of the pump, as well as a 150 μm thick silicon membrane, are designed and fabricated using only three pattern process steps. An actuator-chamber and a pump-chamber with depths of 250 μm are formed after 250 min KOH etching, while the diffuser/nozzle element with a depth of 50 μm is sequentially formed after chamber forming.
Aside from sensing, microfluidic and pumping elements, the chemical sensor system needs a microgenerator and energy storage unit to function. A piezoelectric micro-power generator (PMPG) device developed has 10 μm SU8 proof mass, 200nm Au /20 nm Cr interdigitated electrode, 1.5 μm functioning PZT layer and 200 nm Si3N4 on 10 μm Si substrate. The Fabricated PMPG vibrates at 61 Hz with power density of 0.29 W/cm3 and can supply 3.33AC voltage, 2.19V DC voltage to the final load [4]. On the other hand, the power storage unit, interdigital structured supercapacitor consists of silicon as the substrate, nickel as current collectors and polyvinyl alcohol based gel as a solid state electrolyte. The maximum charge density value is 4.1×10 -6 pC/ μm 2 and the maximum capacitance achieved is 0.116pF [5]. The combined system realised a stand-alone chemical sensing device for biomedical applications.
[1] TY Tiong; CF Dee; AA Hamzah; BY Majlis; SA Rahman. 2014. Enhancement of CuO and ZnO nanowires methanol sensing properties with diode-based structure. Sensors and Actuators B: Chemical, 202: 1322-1332
[2] M Masrie; BY Majlis; J Yunas. 2014. Fabrication of multilayer-PDMS based microfluidic device for bio-particles concentration detection. Bio-Medical Materials and Engineering, 24 (6): 1951-1958

[3] J Yunas; J Johari; AA Hamzah; BY Majlis. 2010. Design and fabrication of MEMS micropumps using double sided etching. Journal of Microelectronics and Electronic Packaging, 7 (1): 44-47
[4] MHS Alrashdan; AA Hamzah; BY Majlis. 2015. Process development of piezoelectric micro power generator for implantable biomedical devices. Micro and Nanosystems, 7 (3): 180-189
[5] HEZ Abidin; AA Hamzah; BY Majlis. 2011. Design of interdigital structured supercapacitor for powering biomedical devices, in 2011 IEEE Regional Symposium on Micro and Nano Electronics
Burhanuddin Yeop Majlis is a Professor of Microelectronics at the Department of Electrical, Electronics and Systems Engineering, Universiti Kebangsaan Malaysia (UKM). He received his Ph.D. in Microelectronics from University of Durham, United Kingdom in 1988, MSc in Microelectronics from University of Wales, UK in 1980, and BSc(Hons.) in Physics from UKM in 1979. He was the Deputy Dean of UKM’s Engineering Faculty from 1995 until 1997. He was also a Research Fellow at the Telekom Malaysia (TM) Research & Development Division, and was the Director of the UKM-TM Microelectronics Research Centre at the Faculty of Engineering, UKM. He was responsible in developing and planning the setting up of the class 1000 and 100 clean room for research at UKM. He had attended intensive industrial training in GaAs MMIC design and manufacturing at GEC-Marconi Material Technology Ltd. United Kingdom.
Currently, Dr Burhanuddin is a Senior Member of the Institute of Electrical and Electronics Engineers (IEEE) and was the Chairman of the IEEE Electron Devices Malaysia Chapter from 1994 to 2006. He is a Fellow member of the Institute of Engineering and Technology (FIET). He is also a Fellow Member of the Malaysian Solid State Science and Technology (FMSSS). He initiated research in microfabrication and microsensors at UKM in 1995 and has also initiated research in GaAs technology with Telekom Malaysia. In 2001 he started research in MEMS with substantial research funding of RM38.2 million from the Ministry of Science, Technology and Innovation. His current interest are design and fabrication of MEMS sensor, RFMEMS, BiOMEMS, Lab on Chip and microenergy and is now the program leader for MEMS research, a National Strategic Research Program. Dr Burhan has published four text books in electronics and one book on Integrated Circuits Fabrication Technology for undergraduate courses and more than 550 academic research papers. His involvement in IEEE and Chair of the Electron Devices Malaysian Chapter for 13 years have given a high impact in the area of semiconductor and microelectronics in Malaysia. His contribution in research activities in this area is very significant. He has initiated a number of research activities in microelectronics and MEMS in Malaysia. He can be considered as a pioneer of MBE-related research in Malaysia via collaborative research with Telekom Malaysia. As a result of his active involvement in IEEE EDS Malaysia, the Chapter is the recipient of the prestigious 2014 EDS Region 10 Chapter of the Year Award.
Dr Burhanuddin is the founder of the first science and engineering-based research institute at UKM, called the Institute of Microengineering and Nanoelectronics (IMEN) in 2002 and has been the Director of IMEN, UKM until now. Under his able leadership, IMEN has been recognized as one of the Centre of Excellence (CoE) of UKM and has been awarded the Nano Malaysia Centre of Excellence by the Ministry of Science, Technology and Innovation (MOSTI) in 2011. In 2014, IMEN was awarded the Higher Institution Centre of Excellence (HiCOE) with research funding of RM5.2 million/year by the Malaysian Ministry of Education (MOE) in the niche field of MEMS for Biomedical (Research Focus: MEMs in Artificial Kidney) which is one of UKM’s research strength. Recently in 2015, he was awarded research grant of RM5 million/year for five years under nanotechnology consortium called NanoMITe. UKM has appointed him to chair the Nanotechnology and Advanced Material Research Niche in UKM which comprises of 34 research groups across science and engineering faculties. He has contributed to the formation of a UKM spin-off company. He has also founded an association to gather all research in nanotechnology in Malaysia, and in 2009, the Malaysian Nanotechnology Association (MNA) was officially established and he was the Founder President until 2012. He was elected as a Fellow of the Academy of Sciences Malaysia (FASc) in April 2014.