Micro-Electro-Mechanical Systems (MEMS) Sensors and Actuators

Performance-on-Demand Micro-Electro Mechanical Systems (POD-MEMS)

The performance of conventional MEMS is limited by its structural and material properties and no two devices have been able to behave identically due to process variation. The goal of PODMEMS (Performance On Demand MEMS) is to not only allow MEMS to correct for process variations, packaging stress, thermal drift and quadrature error, but also to increase the utility of MEMS by extending their behavior beyond conventional mechanical limits. This is done by imparting active electrical feedback forces onto MEMS that mimic additional mechanical forces. In doing so, MEMS will be able to modify their apparent mass, damping, and stiffness, whereby changing their performance on demand. Our analysis suggests that if feedback force is proportional to sensed displacement, velocity, or acceleration of a MEMS proof mass, then feedback can be used to increase or decrease the apparent stiffness, damping, or mass of the system. We develop an analytical steady-state MEMS model that includes feedback forces and circuit delay, and we develop a stability model. Our analytical models are verified using numerical simulations that include circuit delay, electrical feedback delay, and noise. Our results support the realization toward performance-on-demand MEMS (PODMEMS). Electrical control of effective damping in any medium will improve the precision of measurement in atomic force microscopy (AFM), optical tweezers, gravitational wave detectors and so on, which is severely limited by the thermally induced fluctuations.

Related manuscript:

• J. Clark, O. Misiats, and S. Sayed, "Electrical Control of Effective Mass, Damping, and Stiffness of MEMS Devices", IEEE Sensors Journal 17, 1363 - 1372, December 2016. (Link).

• S. Sayed and J. V. Clark, "Active control of effective mass, damping, and stiffness of MEMS", Symp. on Design, Test, Integration & Packaging of MEMS/MOEMS, pp.1-7, Barcelona, Spain, April 2013. (Link).

• S. Sayed, N. D. Andrews, J. V. Clark, “Towards Electrostatic Force-Feedback for Reducing Thermally-Induced Vibration of MEMS”, Proc. IMECE, ASME, November 2012. (Link).

• S. Sayed, "Performance-on-Demand MEMS (PODMEMS): Electrical Control of Effective Mass, Damping, and Stiffness" (2013). Open Access Theses. 90. (Link).