MEMS Piezoelectric Vibration Energy Harvester with Three-DOF Responses

© ASEE 2015Vibration energy harvester can convert mechanical vibration energy into electrical energy and store it in battery for later use. It can create clean renewable energy from vibration movements such as walking, jumping, running, etc. This can convert energy previously wasted into useful energy for charging portable electronic devices, wireless sensors. If such devices are widely used, it can generate a large amount of green energy and help protect the environment. Most MEMS energy harvesters are designed to harvest energy from one direction only. In this research, a MEMS piezoelectric vibration energy harvester with three-DOF (degree-of-freedom) responses is proposed. The device consists of two silicon masses suspended by two sets of T-shape beams from both sides. The four sets of folded beams in both sides allow the mass to vibrate along the X direction. The two sets of straight beams allow the mass to vibrate along both Y and Z directions. The Piezoelectric material is pre-deposited along the surfaces of the beams. It can convert the vibration energy of beams into electric voltage, which is passed through a rectifying circuit to charge a battery. The device can harvest vibration energy along all three axes, resulting more effective energy harvesting outcome. It is designed and simulated in COMSOL. The proposed MEMS energy harvester can be attached to shoes, tires or other vibrating surfaces to harvest energy from the movement of walking, running, driving for clean energy generation.Electrical Engineering Department, School of Engineering, University of Bridgeport