Feasibility Study of Thermal Actuators for MEMS Variable Emittance Radiators
Based on COMSOL Multiphysics® software, an analysis of an innovative thermal actuation system capable of overtaking the traditional electrostatic comb drive, nowadays used for actuating the shutter array of variable emittance radiators, has been conducted as to validate this technology for the future active thermal control of CubeSats operating in an harsh environment, where thermal actuators overtakes comb drives due to their higher radiation hardness. Actuators based on thermal expansion effect can provide a large force and a deflection perpendicular or parallel to the substrate. They have been shown to be a valuable complement to electrostatic actuators. In particular, polysilicon thermal actuators can operate in an integrated circuit (IC) current/voltage regime and may be fabricated by a surface–micromachining technology.