Electrostatic spring effect on the dynamic performance of microresonators

Abstract

This paper reports on the significant discrepancy between the analytical and experimental resonant frequencies of folded beam micro resonators. Experimental results for the resonant frequency showed a consistent 20% discrepancy over theoretical and finite element results. Possible causes of the discrepancy from tapered cross section of the flexure beams, dimensional variations and electrostatic spring effects are discussed and shown to contribute to the significant difference between analytical and experimental values. IntelliCAD™ electrostatic simulation was done to isolate the electrostatic spring effect and compared with the experimental observations. The compliance due to AC voltage has also been observed in DRIE resonators.