Resonant Micro and Nano Electromechanical Systems

Over the past decade, breakthrough researches in micro-electromechanical systems (MEMS) have enabled drastic performance enhancement in silicon-based sensors, actuators and signal-processing elements. Nano-precision mixed-mode fabrication processes have enabled the realization of record high-Q and high-frequency electrostatic and piezoelectric resonant microdevices in silicon, bringing new life to MEMS and creating exciting new research horizons.

This talk will first discuss ultra high-Q single-crystal-silicon resonators with nanometer-gap vertical electrostatic transducers. Temperature-stable all-silicon bulk acoustic reference oscillators in the VHF and UHF range have been demonstrated with phase noise characteristic equivalent to that of bulky quartz-based oscillators. Thin-film encapsulation of the embedded silicon resonators have shown to provide hermetic sealing for such devices, enabling low-profile IC-like packaging for high-volume applications. Recently, we introduced electrostatic bulk acoustic wave inertial sensors which show great promise in enabling inertial-navigation on-a-chip due to their superior stability and high Q.

Recent research has also shown tremendous opportunity for micro and nano mechanical systems in RF applications such as multi-standard wireless systems. I will discuss a project in which we study arrays of piezoelectrically-transduced acoustic filters in ultra-nano-crystalline diamond and single-crystalline silicon to implement analog spectral processors for cognitive radio. In addition, I present record high-Q (low insertion loss) tunable lumped-element filters in silver that are post-CMOS-compatible and wafer-level-encapsulated using a thermally-decomposable polymer packaging technique.

Last but not least, I will discuss gravimetric resonant arrays for detection of biochemical and biological agents. Functionalized bulk-mode nanomechanical resonators offer unique characteristics for large dynamic-range chemical and biological detection in harsh gaseous and aqueous environments. However, several challenges lie ahead that will be discussed in the talk.

Farrokh Ayazi is an associate professor in the School of Electrical and Computer Engineering at the Georgia Institute of Technology. He received the B.S. degree in electrical engineering from the University of Tehran, Iran, in 1994 and the M.S. and Ph.D. degrees in electrical engineering from the University of Michigan, Ann Arbor, in 1997 and 2000, respectively. His research interests are in the areas of integrated micro- and nano-electromechanical resonators, IC design for MEMS and sensors, RF MEMS, inertial sensors, and microfabrication techniques.

Dr. Ayazi is an editor for the IEEE/ASME Journal of Micro-Electro-Mechanical Systems, and serves on the technical program committees of the IEEE International Solid State Circuits Conference (ISSCC), and the International Conference on Solid State Sensors, Actuators and Microsystems (Transducers). In the past, he has served on the technical program committees of the IEEE MEMS and IEEE Sensors conferences. Dr. Ayazi is a 2004 recipient of the NSF CAREER Award, the 2004 Richard M. Bass Outstanding Teacher Award (determined by the vote of the ECE senior class), and the Georgia Tech College of Engineering Cutting Edge Research Award for 2001–2002. He received a Rackham Pre-doctoral Fellowship from the University of Michigan for 1998–1999.