In-situ characterization of ferromagnetic shape memory alloy / silicon bimorph nanoactuators

Abstract

Nano scale actuators consisting of a free-standing bilayer of ferromagnetic shape memory alloy (FSMA) and silicon with critical lateral dimensions of 250 nm are designed, nanofabricated and characterized in-situ in a scanning electron microscope (SEM). Upon Joule heating and cooling, fully reversible nano actuation in out-of-plane direction of up to 4 % of actuator length is observed. In-situ measurements allow the correlation of resistivity and deflection revealing the presence of the shape memory effect superimposing the bimorph thermal expansion.