Planar Nanoactuators Based on VO₂ Phase Transition.

Abstract

Actuation at micro- and nanoscale often requires large displacements and applied forces. The high work energy density that lies inside many phase transitions is an appealing feature for developing new actuating schemes, especially if the transition is reversible and scalable into small actuating domains. Here, we show the fabrication of a planar nanomechanical actuator having chevron-type geometry and based on the phase transition of VO₂. This device is thermally activated through heating just above room temperature to trigger the VO₂ crystalline symmetry change associated with the metal-insulator transition. The large lattice expansion of VO₂ phase transition, compared to standard materials, is further amplified by the chevron-type geometry. DC and AC operation of the device are discussed.