Design and kinematic modeling of a planar piezo-actuated multistage compliant mechanism

Abstract

Multistage compliant mechanisms have been widely investigated in recent decades oweing to their multiplying displacement amplification and compact structure. This paper presents a new planar multistage compliant mechanism with no assembly errors, relatively high frequency response and large range. By defining an impedance factor to describe the hindering effect of the second layer on the preceding one, the combined displacement amplification ratio of the proposed multistage compliant mechanism is theoretically modeled based on the elastic beam theory and the principle of conservation of energy. Initial prototype is monolithically fabricated and experimentally tested. It exhibits a natural frequency of 987Hz and displacement of more than 260μm, which agrees well with the finite elemental results and the theoretical predictions. The accuracy of the proposed model and the vibration modal is also verified, which may be a versatile tool for designing.