BioMEMS Research Group
Technical leader: Assoc. Prof. Dr. Haluk Külah
Group Members (Alphabetical Order):
- Aziz Koyuncuoğlu (M.Sc. student)
- Deniz Eroğlu (M.Sc. student)
- Deniz Ertürkan (M.Sc. student)
- Ender Yıldırım (Ph.D. candidate)
- Hatice Ceylan (Ph.D. candidate)
- Yağmur Demircan (M.Sc. student)
- Dr. Yekbun Adıgüzel (Post-Doc)
- Sertan Sukas (M.Sc., 2007)
- Ata Tuna Çitlik (M.Sc., 2008)
- Gürkan Yılmaz (M.Sc., 2011)
- Ekrem Bayraktar (M.Sc. 2011)
- Theoretical design and analysis of BioMEMS sensors
- Theoretical design and analysis of microfluidic components
- Finite element modeling
- Analytical modeling of complete BioMEMS sensor systems
- Glass micromachining
- SOI micromachining
- Si micromachining
- Parylene Suspended Channel Fabrication
- Parylene wafer bonding (Si-to-glass)
- Circuit design
- Low-noise preamplifier design
- Closed-loop controller design
- Temperature controller design
- Wafer-level testing of fabricated BioMEMS sensors
- Device-level testing of system and its submodules
- Performance characterization of BioMEMS sensor systems
BioMEMS sensors research has been initiated at METU in 2004. Over the years, the group has conducted research on various topics with the following milestones:
- 2004: Development of the concept of a double channel micro electrophoresis system utilizing heteroduplex analysis.
- 2004: In-house MEMS fabrication of the first electrophoresis prototypes using glass surface micromachining process associated with suspended parylene channel
- 2006: Started development and fabrication of an Electrostatic Actuated Micro Valve
- 2007: Completion of micro-electrophoresis project (TUBITAK 104S605)
- 2007: Started development and implementation of electrochemical DNA sensor for clinical applications
- 2008: Started development and fabrication of silicon-on-insulator (SOI) resonator process
- 2008: Started development and fabrication of a microchannel heat exchanger for electronic cooling applications..
- 2008: Started development and fabrication of dielectrophoretic separation devices with spiral channels and concentric electrodes
- 2009: Started development and fabrication of a free-to-rotate check valve using FeNi electroplating
BIOMEMS Group Research TOPICS
Electrophoretic DNA Mutation Analysis Based on MEMS Technology
Identification of human disease causing mutations and gene polymorphisms is becoming more important especially after the completion of the Human Genome Project. As polymorphisms are revealed to possibly calculate personal risks for complex diseases, designing drugs specific for a genotype will be the next step in medicine to improve human health. The logical method for identification of mutations or polymorphisms may seem to be sequencing of candidate genes; however, due to high costs involved especially for very large genes, sequencing is not yet the most convenient method in standard research laboratories. We, therefore propose to use BioMEMS technology to solve the modern day demands of molecular biology research. BioMEMS has already become a promising field for medicine by introducing smart drug delivery machines and devices to measure blood values. The specific aims of this research proposal are to 1) develop a DNA electrophoresis chip by MEMS technology and 2) optimize the electrophoresis chip for mutation analysis. With the development of such an electrophoresis chip, we aim to lower the costs of mutation analysis as well as to decrease the time required to run macro size mutation analysis gels. Development of such a system will also contribute to the field and pioneer studies for the development of DNA sequencing on chips. Ultimately, expensive and time consuming procedures of today's research tools will be performed on inexpensive chips in a matter of minutes.
Design and Implementation of Disposable MEMS based DNA Electrochemical Biosensor for the Detection of Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus Species (mecA, VanA and VanB genes) for Clinical Purposes
The project is on design and implementation of disposable MEMS based DNA electrochemical biosensor for the detection of Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus Species (mecA, VanA and VanB genes) for clinical purposes. This study is conducted in the collaboration of Department of Clinical Microbiology at Hacettepe University, Department of Electrical and Electronics, and Department of Chemical Engineering at METU. Our ultimate goal is to detect 10nM DNA with the combination of advantages of molecular methods and MEMS technology. Currently, we are working on optimization of microelectrodes’ dimensions and their fabrication.
Design and Implementation of Micro valves for BioMEMS Applications:
BioMEMS applications or Lab-on-a-Chip devices naturally involve capillary or pressure driven lateral micro flows. In either case, mixing, metering, switching, and separation of one or more species, body fluids and/or reagents should be done to carry out biological analyses. Active and passive micro valves are commonly used in these unit operations. This project involves design and implementation of active in-plane MEMS micro valves for use in pressure driven lab-on-a-chip applications.
Design Implementation and Fabrication of a Gravimetric rare cell detector with closed loop electronics:
As the micro and nanotechnology has evolved and shrunk down to dimensions comparable with biologic items, the idea of interacting with biological molecules, cells, and biological processes by using man-made devices has become feasible. Today, multidisciplinary engineering disciplines are aiming to produce devices by combining old fabrication methods for micro scale devices, new polymer micromachining technologies, mechanics, electronics, chemistry, metallurgy, and biology. In contrast with expensive, time consuming, and relatively low resolution old macro technology, miniaturized systems can perform same analyses with much lower cost, much faster, and with very high resolution. Additionally, portability is a great advantage which eliminates the need for laboratory environment requirement needed for most analyses. Moreover, integrated systems with sample-in answer out capability also remove trained personnel requirement that are needed to operate and maintain macro systems. Cell based techniques are used to diagnose and study diseases like cancer and AIDS, and number of these techniques being implemented with BioMEMS devices is proliferating. Moreover, biomedical microsystems can push the detection limits down to single cell per sample, a development that not only allows very-early diagnosis but also constitutes an enabling technology for cell biology and medicine. This promising technology is called micro scale rare cell detection. This project aims to develop a novel rare cell detection system potentially capable of detecting single cell per sample. Systems exploits resonant frequency change when a mass bound occurs on top of the proof mass. Project is supported by TUBITAK (The Scientific and Technological Research Council of Turkey) with grant number 109E066.
Cell/Particle Separation using Dielectrophoresis
Aim of this project is to differentiate cells possessing different electrical properties. When electrical parameters of cells are considered, numerous methods can be expressed at first glance. Dielectrophoresis, which is manipulation of dielectric particles which have different polarizability with respect to the medium they have suspended in, is one of these electrical separation methods. Due to the square law nature of the dielectrophoretic force, there is no polarity concern as in the electrophoresis. Thus using low voltages, huge forces can be created in short distances. In this project spiral microchannels enhanced with concentric electrodes are employed according to the optimization parameters in the design phase.
Check Valve Project
In this project a free-to-rotate check valve has been designed. As indicated in the literature, many systems require high diodicity profile in micro total analysis systems. The aim of the project is to design and fabricate a check valve which has a stationary and a rotary part and implement it into a micro channel.
First Generation micro-electrophoresis devices with temperature control
SEM pictures of suspended parylene channels
Detailed explanation of micro-electrophoresis chip and SEM pictures of U-turns and channel crossings
All polymer micro-electrophoresis chip
Test Setup at 2004
Test Setup in clean room environment at 2010
Clean Room Equipments
Clean Room Equipments
Second generation micro-electrophoresis device employing heteroduplex analysis with double channel
Packaged first version micro-electrophoresis
Electrostatic Actuated Parylene Micro Valve
Wafer level and close-up views of dielectrophoretic spiral chromatography device with concentric electrodes created with Au electroplating
Microchannel Heat Exchanger Test Device, (a) Complete Device, (b) Close-up, (c) SEM, (d) Fluidic Connection