Pull-in behavior and multistability of a curved microbeam actuated by a distributed electrostatic force

In this work we report on theoretical and experimental investigation of a multistability phenomenon in initially curved flexible clamped-clamped microbeams actuated in-plane by a distributed electrostatic force and fabricated from silicon on insulator (SOI) wafer using a deep reactive ion etching (DRIE) process. Theoretical results provided by a reduced order (RO) model of the shallow Euler-Bernoulli arch and backed by experiments indicate that in the device with non-monotonous stiffness-deflection dependence the voltage-deflection characteristic may have two maxima implying the existence of multiple stable configurations at the same voltage while the range of stable deflections is significantly larger and pull-in voltage is lower than in a straight beam.