F. Levent Degertekin

Professor

Office:	Love, Room 320
Phone:	404.385.1357
Fax:	404.894.8496
E-mail:

Education

• Ph.D. (EE), Stanford University, 1997
• M.S. (EE), Bilkent University, Turkey, 1991
• B.S. (EE), Middle East Technical University, Turkey, 1989

Research Areas and Descriptors

• Microelectromechanical Systems and Acoustics and Dynamics; Micromachined ultrasonic and opto-acoustic transducers, atomic force microscopy, and medical ultrasound imaging.

Background

Dr. Degertekin worked in the area of acoustic microscopy, ultrasonic sensors for semiconductor processing and modeling of wave propagation in layered media before focusing on microscale devices. Dr. Degertekin began at Georgia Tech in 2000 as an Assistant Professor. Prior, he was an Engineering Research Associate at the E. L. Ginzton Laboratory at Stanford University.

Research

Dr. Degertekin’s research focuses on understanding of physical phenomena in acoustics and optics, and utilizing this knowledge creatively in the form of microfabricated devices. The research interests span several fields including atomic force microscopy (AFM), micromachined opto-acoustic devices, ultrasound imaging, bioanalytical instrumentation, and optical metrology. Dr. Degertekin’s research group, in collaboration with an array of collaborators, has developed innovative devices for applications such as nanoscale material characterization and fast imaging, hearing aid microphones, intravascular imaging arrays for cardiology, bioanalytical mass spectrometry, and microscale parallel interferometers for metrology.

The research in atomic force microscopy uses micromachining technology to implement novel probes and actuators for fast imaging, single molecule force spectroscopy, and quantitative material characterization and subsurface imaging at the nanoscale. This effort has resulted in the FIRAT (force-sensing integrated readout and active tip) structure which combines integrated electrostatic actuation and optical interferometer for sensitive force detection in a microscale AFM probe (http://www.gatech.edu/news-room/release.php?id=858). The speed and controlled dynamics of this probe is exploited for fast topography and TRIF (time resolved interaction force) mode imaging. Another aspect of the AFM research explores the imaging capability of this instrument for subsurface defects that can be found in semiconductor electronics structures through modeling and experiments. The work on single molecule force spectroscopy is performed in collaboration with Professor Cheng Zhu, and aims to increase the throughput by parallel operation of membrane based probes as well as to improve the resolution and speed to widen the application space of this technique.

The group’s research on capacitive micromachined ultrasonic transducers (CMUTs) focuses on development of new CMUT structures with improved performance using the advantages of microfabrication technology, and design and implementation of catheter based imaging arrays for intravascular and intracardiac ultrasound imaging for interventional cardiology applications. These CMUT arrays are fabricated using low temperature processes enabling post-CMOS electronics integration. The projects in this area involve transducer design, array and image processing algorithm development, custom CMOS electronics design and fabrication, and finally evaluation of the devices on phantoms and animal models. This work is performed in collaboration with Prof. Paul Hasler (GT ECE) and Prof. Mustafa Karaman (Isik University, Turkey).

In the area of micromachined microphones, Dr. Degertekin’s group has developed opto-acoustic devices that use miniature interferometric displacement readout systems based on optical gratings. This approach decouples the electronic readout sensitivity and the mechanical pressure sensitivity:  a significant bottleneck for conventional capacitive microphones. This approach is also used to implement novel biomimetic directional microphones for hearing aids in a project performed in collaboration with Prof. Ron Miles of Binghamton University. Current focus of the research thrust is to use the electrical port available in these optical microphones for force feedback. With the extremely sensitive built-in optical interferometer, this approach may lead to highly sensitive micromachined microphones with low thermal mechanical noise and broad bandwidth, and  micropohone arrays suitable for small, high sensitivity sound intensity probes.

The work in the Degertekin lab exposes the students to applied physics, electrical, mechanical and biomedical engineering, biology and biomimetic systems and to latest technology for microscale and nanoscale device development. In the end, the students get a thorough theoretical and experimental education in acoustics and optics, while learning to perform interdisciplinary research.

Distinctions

• Institute of Electrical and Electronics Engineers
• Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Outstanding Paper of the Year, 2004
• Sensors Journal, Associate Editor 2003-2005
• Ultrasonics Symposium Best Student Poster Award in Transducers and Transducer Materials for Jeff McLean, Rasim O. Guldiken, and Sheng-Yu Peng (Ph.D. students) in 2003, 2005 and 2006, respectively
• Georgia Institute of Technology
  • Woodruff School Faculty Fellow, 2008-2013
  • Sigma Xi (Georgia Tech Chapter) Young Faculty Award, 2005
• National Science Foundation Faculty Early Career Development Award, 2004-2009
• Whitaker Foundation Biomedical Engineering Research Grant Award, 2001

Selected Patents

• Integrated Micro Fuel Processor and Flow Delivery Infrastructure, U.S. Patent 7,312,440, with A. G. Fedorov, December 25, 2007
• Electrospray Systems and Methods, U.S. Patent 7,208,727, with A.G. Fedorov, April 24, 2007
• Highly-sensitive Displacement-Measuring Optical Device, U. S. Patent 7,116,430, with N. A. Hall and W. Lee, October 3, 2006.
• Method and Apparatus for the Ultrasonic Actuation of the Cantilever of a Probe-Based Instrument, U.S. Patent 6,779,387, August 24, 2004
• Microinterferometer for Measuring Distance with Improved Sensitivity, U. S. Patent 6,753,969, with T. Kurfess, B. Kim, and H. A. Razavi, June 22, 2004
• Optical Displacement Sensor, U. S. Patent 6,567,572, with G. G. Yaralioglu and B. T. Khuri-Yakub, May 20, 2003
• Wide Frequency Band Micromachined Capacitive Microphone/Hydrophone and Method, U. S. Patent No. 6,493,288, with B. T. Khuri-Yakub, A. Atalar, and S. Ergun, December 10, 2002

Representative Publications

• H. Torun, et al. 2007. Micromachined Membrane-Based Active Probe for Biomolecular Mechanics Measurement. Nanotechnology 18, 165303.

• A. G. Onaran et al. 2006. A New Atomic Force Microscope Probe with Force Sensing Integrated Readout and Active Tip. Review of Scientific Instruments 77, 023501.

• R. O. Guldiken, J. McLean, and F. L. Degertekin. 2006. CMUTs with Dual-electrode Structure for Improved Transmit and Receive Performance. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 53, 483-491.

  N. A. Hall, et al.  2005. Micromachined Microphones with Diffraction-Based Optical Displacement Detection. Journal of the Acoustical Society of America 118, 3000-3009.
    
  S. Aderogba, et al. 2005. Nanoelectrospray Ion Generation for High Throughput Mass Spectrometry Using a Micromachined Ultrasonic Ejector Array. Applied Physics Letters 86, 203110.