Probing Multimode Thermoelastic Damping in MEMS Beam Mass Structure

Abstract

Introduction Thermoelastic damping (TED) is a significant contributor to mechanical damping in micro-sized structures. Design variables to tune damping and natural frequency include material type, boundary conditions, structural geometry, and vibration modes. However, there is an incomplete report on the effects of different mode-shapes on TED.

Materials and Methods Dependency of TED on fexural mode-shapes of clampedclamped MEMS beam mass structure has been numerically investigated in this study.

Results Multimode TED quality factor characterizing diagram with multimode curves has been obtained, combining quality factor dependency on frequency by mode-shapes, beam thickness, and nodal masses.

Conclusions The TED quality factor plot or multimode TED curves presented clarify the ambiguities of TED frequency dependency on mode-shapes and could be very revealing in any generic mode selection problem on device design requiring higher order modes with TED consideration.