Modeling and Analysis of Energy Harvester Based on Material Work Function

Abstract

The energy harvesting is an important phenomenon that is used in various applications and devices especially to power micro scaled devices in MEMS. There are different types of energy harvesters that are available for such applications and the output of all these devices is based on various working-principles. In all of these existing energy harvesters, the initial biasing with an external battery is required. But in case of work function based energy harvester, the two plates of two different materials when get into galvanic contact with each other then the surface charge from one plate, with low work function value, will move towards the other plate of metal having high work function value. Due to this movement of charge from one plate to other, the two plates become oppositely charged and behave like parallel plate capacitor. There is no any external biasing is needed in work function based energy harvester and this feature makes it special among all other types of energy harvesters. To verify this phenomenon, an experimental set up is designed that can test the effects of change of model parameters like areas of plates, type of materials, shapes, thickness of plates and vibration frequencies of system etc. We used different samples of different sizes made from zinc, aluminum, cadmium and copper metals & we did testing on some N-type and P-type semiconductor materials as well to observe the effect of semiconductor material, area and shape of plates on output parameters of energy harvester. We carried out the simulation of the work in different available simulators to predict the best combination of model parameters for MEMS applications