Design and simulation of MEMS based radioisotope converter with electrostatic capacitive energy conversion mechanism

This paper presents the design and simulation of electrostatic capacitive vibration-to-electricity energy conversion system based on radioisotope Ni⁶³ that produces low energy beta particles. The electrostatic capacitive energy conversion utilizes a variable capacitor to convert radioisotope energy into electrical energy by mechanical vibration as transformed intermediate. The MEMS capacitor is designed as a radioisotope actuated parallel-plate spring-mass-damping structure fabricated through the mature silicon-based micromachining processes. Numerical simulations are performed in order to optimize design parameters targeting a maximum output power. Such a MEMS based energy converter is able to provide an average output power of 0.0812 μW·cm^-2 and energy conversion efficiency of about 4% according to the radioisotope activity of 10 mCi·cm^-2.