Design and implementation of A MEMS based gravimetric detector for cytometry applications

Bayraktar, Ekrem
This thesis reports design and implementation of a MEMS based gravimetric resonator for cytometry applications. There are mainly two objectives of this thesis; to enable in-flow analysis and to perform closed loop operation that does not require any additional processing or equipment. A novel MEMS based resonator with in-flow capabilities is proposed for detection of agents inside micro channels. High resolution of mass detection inside micro channels is planned to be succeeded with lateral motion in the micro channel floor. The idea embedding lateral resonators emerges from decreasing squeeze film damping during the motion of the resonator. Lateral motion is supported by hydrophobic parylene coating to decrease the damping. Theory and design of the gravimetric resonators are explained and the fabrication flow is constructed and performed successfully by combining SOI, SOG and polymer micro fabrication techniques. Problems during the fabrication are overcome and optimized flow is presented. The devices have a foot print area of 1.5 x 0.5 cm2 which is mainly composed of reservoirs for fluidic connections. Ten types of devices are designed according to their mass sensitivities and compliances. Trade offs between frequency, injected current, and compliance are analyzed successfully by taking also the performance parameters of the interface electronics in to account. Test results reveal that single latex bead with 3 µm diameter and 14.127 pg mass can be sensed successfully and mass sensitivity is measured to be 5.91 fg/Hz for this type of device.


Design and implementation of a mems based spiral channel dielectrophoretic separator for cytometry applications
Yılmaz, Gürkan; Külah, Haluk; Department of Electrical and Electronics Engineering (2010)
This thesis reports design and implementation of a MEMS based spiral channel dielectrophoretic separator for cytometry applications. Main objective of the thesis is to separate leukemia cells from healthy leukocytes with respect to the differences in their dielectric properties. A novel MEMS based dielectrophoretic separator with spiral channels and concentric 3D electrodes has been proposed. The proposed geometry decreased the footprint, which reduces the device cost, without degrading the separation and q...
Development of a resonant mass sensor for MEMS based cell detection applications
Eroğlu, Deniz; Külah, Haluk; Department of Electrical and Electronics Engineering (2012)
This thesis reports design and implementation of a MEMS based resonant mass sensor for cell detection applications. The main objective of the thesis is the real-time detection of captured cells inside liquid medium and obtaining the detection results by electronic means, without the aid of any external optical instruments. A new resonant mass sensor architecture is presented that has various advantages over its conventional counterparts. The device oscillates in the lateral direction, eliminating squeeze fi...
Design of a Novel THz Sensor for Structural Health Monitoring Applications
Pavia, J. P.; Ribeiro, M. A.; Sarikaya, C. K.; Akbar, D.; Altan, Hakan; Souto, N. (2019-01-01)
In this paper, we propose a study on the characterization, design and simulation of a THz sensor for applications in Structural Health Monitoring (SHM). The proposed sensor is assembled using two frequency selective surfaces (FSSs) based on metamaterial wire resonators. We present a theoretical model to describe its electromagnetics which is used not only to understand the physical principles underlying the functioning of the sensor but also to determine a set of optimized parameters for its operation in th...
Design and implementation of low leakage MEMS microvalves
Yıldırım, Ender; Külah, Haluk; Arıkan, Mehmet Ali Sahir; Department of Mechanical Engineering (2011)
This thesis presents analysis, design, implementation, and testing of electrostatically actuated MEMS microvalves. The microvalves are specifically designed for lab-on-a-chip applications to achieve leakage ratios below 0.1 at pressure levels in the order of 101 kPa. For this purpose, two different microvalves are presented in the study. In the proposed designs, electrostatic actuation scheme is utilized to operate the microvalves in normally open and normally closed modes. Characterization of normally open...
Design and Implementation of a Current-Source Converter for Use in Industry Applications of D-STATCOM
Bilgin, Hazim Faruk; Ermiş, Muammer (2010-08-01)
This paper deals with the design and implementation of the power stage of a forced-commutated current-source converter (CSC) for use in industry applications of distribution type static synchronous compensator (D-STATCOM). The power semiconductors are switched at 500 Hz according to the switching patterns generated by selective harmonic elimination method for the elimination of the most significant four low-order harmonics. The possibility of using various power semiconductors in CSC is examined both theore...
Citation Formats
E. Bayraktar, “Design and implementation of A MEMS based gravimetric detector for cytometry applications,” M.S. - Master of Science, Middle East Technical University, 2010.