4-DOF SOI-MEMS ultrasonic energy harvester

A silicon-on-insulator microelectromechanical systems (MEMS)-based energy harvester potentially suitable for applications such as implanted biomedical systems is presented. Designed to be mechanically excited by an external source of ultrasonic waves, the harvester features a novel 4-degree-of-freedom resonant mechanism that allows the device to generate electrical energy in any orientation. Experimental testing of the fabricated harvester shows that the device is able to generate 50.9nW, 60.6nW, and 14.3nW of electrical power when excited by ultrasonic waves directed from the x, y, and z directions, respectively.