A New Electrothermal Microactuator with Z-shaped Beams

A new class of thermal microactuators, Z-shaped thermal actuator, is introduced in comparison with the wellestablished V-shaped thermal actuator. Though they share many features in common, Z-shaped thermal actuator offers several advantages: compatibility with anisotropic etching, smaller feature size, larger displacement, and larger variety of stiffness and output force. While the Z-shaped thermal actuator was modeled analytically and verified by multiphysics finite element analysis (FEA), the beam width and length of the central beam were identified as the major design parameters in tuning the device displacement, stiffness, stability and output force. Experimental measurements were taken on three arrays of Z-shaped thermal actuator with variable parameters. Results agreed well with the finite element analysis. The development of Zshaped thermal actuator is applicable in simultaneous sensing and actuating applications. During the quasi-static test of individual Z-shaped thermal actuator, the average temperature in the device structure was estimated based on electric resistivity at each actuation voltage.