Special Seminar: Friday, January 11, 2008
2:00 pm – 3:00 pm
CISX-101 (snacks at 1:45)
Building Blocks for Silicon MEMS Timers
and Signal Processors
Dr. Ashwin Seshia
Lecturer in MEMS and Fellow, Queens’ College
Dept. of Engineering, University of Cambridge
This talk will introduce new building blocks and concepts for silicon-on-insulator
based MEMS resonator technology with a focus on developments at the device and
circuit levels. A comparison is drawn between different transducer technologies and
resonator topologies with a view towards frequency scaling and power handling. Linear
and nonlinear circuit topologies are introduced for silicon micromechanical resonator
based oscillators with a view towards compensating extremes of capacitive and
motional parasitics inherent in the hybrid integration of MEMS with CMOS while
simultaneously optimising for low phase noise and power dissipation. Scalable filter
topologies based on mechanically and electrically coupled resonant modes in silicon
microstructures are presented. Reverse-biased pn junctions embedded in silicon
microresonators are introduced as an alternative, CMOS compatible transducer with
beneficial scaling for NEMS applications.
Ashwin A. Seshia received the B.Tech. in engineering physics from IIT – Bombay in
1996 and the M.S. and Ph.D. degrees from UC Berkeley in electrical engineering in
1999 and 2002. His Ph.D. thesis demonstrated the theory and operation of an
integrated MEMS resonant-frequency-shift output vibratory rate gyroscope. He is
presently a member of the faculty of the Cambridge University Engineering Department
where he is Lecturer in micro electromechanical systems (MEMS), a Fellow of Queens’
College and a member of the Micromechanics and Nanoscience research groups. His
research interests include integrated micromechanical resonant structures for sensor and
timing applications, micromachined devices for in-vivo monitoring, and biological
sensor systems.