Localized Mechanical Actuation using pn Junctions.

We are reporting on the fabrication and characterization of microscale electromechanical actuators driven by the internal forces induced within the depletion region of a typical pn junction. Depletion region actuators operate based on the modulation of the interactions of the internal electric field and the net space charge within the depletion region of a pn junction by an external potential. In terms of performance, depletion region actuators fall between electrostatic actuators, where a physical gap separates the charges on two electrodes, and piezoelectric actuators, where the separation between the charges is on the order of lattice constants of the material.