LARGE-DEFLECTION EFFECT ON THERMOELASTIC DISSIPATION OF MICROBEAM RESONATORS

In real applications, beam resonators in MEMS/NEMS often vibrate beyond the linear regime. The present paper aims to study the effect of large-deflection on thermoelastic dissipation of doubly-clamped microbeam resonators. Detailed formulas are derived for quality (Q-) factor due to thermoelastic dissipation which depends on the amplitude of vibration deflection. Under adiabatic or isothermal surface thermal conditions, the nonlinear effect of large-deflection on thermoelastic dissipation is demonstrated with a comparison to the results based on linearized small deflection vibration. Our results show that thermoelastic dissipation is reduced monotonically with increasing amplitude of vibration deflection under adiabatic surface condition, while thermoelastic dissipation is increased monotonically with increasing amplitude under isothermal surface condition. Under both adiabatic and isothermal surface conditions, the large-deflection effect on thermoelastic dissipation becomes more significant for higher vibration frequencies than lower ones. For the first time to the best of our knowledge, these results reveal that large deflection has a significant effect on thermoelastic dissipation of microbeam resonators and surface thermal condition plays an important role in the large-deflection effect.