Mechanical springs, electrostatic anti-springs and MEMS parametric reasonators

Prof. David Elata, Technion – Israel Institute of Technology

‘Electrostatic MEMS resonators combine the high quality factor attainable in vibrating microstructures, with the flexibility of electrostatic driving and sensing. Electrostatic resonators have been developed for signal filtering, clocking, and sensing applications, and since their introduction five decades ago, much effort has been invested to improve their performance.
The folded-beam suspension has been used as the spring of choice in many electrostatic comb-drive resonators for over 30 years. It was assumed to respond as a linear spring, but this is actually true only for static states. Resonators vibrate harmonically, and in these conditions the response of the folded-beam suspension is nonlinear. I will present the new dynamically balanced folded-beam suspension, in which this nonlinearity is avoided.
In recent years much attention is given to parametric resonators. We have used electrostatic anti-springs to implement a Meissner parametric resonator. I will present a model which gives a simple and intuitive explanation of parametric resonance, and I will show how it relates to the Meissner case. I will discuss two interesting features of the Meissner resonator: crossover points in the stability map, and the effect of damping at consecutive resonances of the 1 degree-offreedom system.

Short Bio
Prof. David Elata, B.Sc. in Mechanical Engineering at the Ben-Gurion University (Israel), M.Sc. in Mechanical Engineering at the Technion – I.I.T. (Israel) and D.Sc. in Mechanical Engineering at the Technion – I.I.T. (Israel), is professor at the Technion – Israel Institute of Technology (faculty of Mechanical Engineering).
His main research interests are: modelling the static and dynamic response of electrostatic microactuators; modelling and development of novel thermoelastic actuation schemes for MEMS devices; modelling the electromechanical response of piezoelectric micro-structures; micro test-devices for measuring mechanical properties; damage mechanics, continuum mechanics, solid mechanics and contract mechanics.
Prof. Elata is member of the editorial board of the IEEE Journal of MicroElectroMechanical Systems.