Analysis and optimisation of MEMS electrostatic on-chip power supply for self-powering of slow-moving sensors

This paper analyses the performance of on-chip motion-driven power generators designed to eliminate wire connections and batteries in embedded sensors. Micro-generators capable of generating enough energy to power sensors have previously been reported. These require high frequency mechanical vibrations to set up the necessary resonance. However, many applications compatible with a human environment do not vibrate; they move slowly and irregularly, and therefore new methods of optimising the power generation are required. Analysis and simulation models to support this are presented for large-amplitude, low-frequency and irregular motion. In order for the generator to continuously achieve the highest possible power generation, the electrostatic force should be constantly reoptimised on-line to account for the actual operating conditions.