Electrostatically-driven active space radiator using near-field thermal radiation

Radiation control is crucial to maintain the operation temperature of satellites under varying irradiation of sunlight. Bulky heat exchangers with heat pipe or thermal louvers/shutters with a low fill factor previously proposed are not suitable for next-generation small satellites. In the present study, we propose an array of electrostatically-driven MEMS diaphragms for active control of thermal radiation using the near-field effect. In between Au and Cu surfaces at 300K, simulated effective emittance drastically increases from 0.1 to 0.8 when the gap is smaller than 0.4 μm. We have also designed and successfully microfabricated a prototype of the MEMS radiators.