Roozbeh Tabrizian received the Outstanding Student Paper Award at the IEEE MEMS 2014 Conference, held January 26-30 in San Francisco. The title of the award-winning paper was "Dual-Mode Vertical Membrane Resonant Pressure Sensor."
Tabrizian is currently a postdoctoral fellow in the Integrated MEMS Laboratory in the School of Electrical and Computer Engineering (ECE), and he graduated with his Ph.D. last December under the direction of ECE Professor Farrokh Ayazi. Ayazi was also a co-author on the paper.
In this paper, Tabrizian and Ayazi presented a micro-mechanical pressure sensor that uses a combination of different resonance modes of a thin vertical silicon membrane for the realization of absolute pressure sensing. The novel combinatorial sensing scheme introduced in this work is based on independent excitation of two high-Q acoustic eigen-modes of the membrane, with a small frequency split but a large difference in sensitivity to the mass-loading effect of ambient gas molecules. A linear combination of these modes is then used as a pressure sensor with an amplified sensitivity.
Such an approach not only improves the sensitivity and resolution, but also obviates the need for low-pressure hermetic encapsulation that is commonly used in MEMS differential pressure sensors. This work is part of the team's research on the investigation and utilization of a piezoelectrically-activated single crystal silicon platform as a test bed for controllable and designable mixed-domain physical interactions. Such interactions can be used for implementation of various low-power micro- and nano-physical sensors that can be integrated on a single die to realize monolithic sensor nodes and single-chip sensor fusion.