ENERGY HARVESTING MEMS USING ALUMINUM NITRIDE

Abstract

Due to scarcity of energy resources, researchers are focusing on self-powered micro systems for variety of applications. The self-powered micro systems include three different transduction mechanisms to convert the vibrational mechanical energy to electrical energy which are: electromechanical, electrostatic and piezoelectric. In which piezoelectric is one of the most important due to its higher energy density, small size and compatibility to micromachining technology. In our work the rcactivcl\ sputtered AIN (aluminum nitride) has been chosen as piezoelectric material due to its compatibility to CMOS technology. The other important piezoelectric material is PZT (lead zirconate titanate), which has been used to compare some of the properties like frequency and D.0 response with AIN. In this work, we fabricate the cantilever beam base vibrational energy harvester, which can extract the vibrational energy to electrical energy. Molybdenum has been chosen as electrode material for the cantilever beam because of its capability to promote a preferential (002) orientation of the AIN and its low resistivity. Due to their particular shape of cantilever, the proposed devices have 3D generation capabilities solving the problem of device orientation and placement in the real application