Spacing-controlling MEMS device for evaluating heat transfer between nanogap

Abstract

Thermionic converter (TIC) using nanogap is expected to be an alternative of thermoelectric generator. Nanogap used in TIC requires few nm gap distance and smooth large area of opposing surfaces, but conventional methods to fabricate narrow nanogap do not meet these requirements. In this report, we fabricated nanogap with 57 nm distance and 21.5 μm² surface area by cleavage of single crystal silicon. Moreover, heat transfer between nanogap was measured while changing gap distance by electrostatic comb actuators. Temperature difference of more than 150K between nanogap was successfully formed, but the heat transfer observed was much smaller than calculation.