Improved Designs for an Electrothermal In-Plane

Abstract—Reported presently are two design approaches to improve the performance of an electrothermal in-plane microactu-ator with “chevron ” beams. One incorporates beams with uniform cross sections but nonuniform lengths or tilt angles to accommo-date the thermally induced expansion of the “shuttle”; the other incorporates beams with nonuniform cross sections to widen the high-temperature “expansion ” zones. It is derived analytically, verified using finite-element simulations, and tested by micro-fabricating actuators occupying a constrained device area that the incorporation of one or the other proposed features leads to an improved performance figure-of-merit, defined to be the product of the actuation displacement and force. An increase in the figure-of-merit by up to 65 % per beam has been measured. [2011-0186] Index Terms—Electrothermal microactuators, in-plane chevron microactuators, microelectromechanical systems (MEMS), optimization. I