Power harvesting using tuned comb drive

Wireless power transfer has gained considerable interest due to its wide range of applications. The power harvesting systems that extract the power from the electromagnetic waves are tuned to the frequency of the incoming signal. In this work, a mathematical model has been developed for MEMS comb-drive which can be used in power harvesting systems, to estimate its resonant frequency. The effects of different design parameters on the resonant frequency have been studied. Simulation results using Coventerware CAD tools indicate that the mathematical model properly predict the response of the MEMS comb drive for different ratio of finger length and finger pitch. The implemented comb drive was also analyzed for its power scavenging capacity. The result shows 592 μJ available energy for an area of 7mm². The simulation results also confirm that the desired frequency is attainable with an accuracy in the range of few hertz.