 June 8, 2007.Researchers at MIT developed the first micro-scale piezoelectric energy harvester using thin film PZT in 2005.Arman Hajati and Sang-Gook Kim invented the Ultra Wide-Bandwidth micro-scale piezoelectric energy harvesting device by exploiting the nonlinear stiffness of a doubly clamped microelectromechanical systems (MEMS) resonator.