Ultra-wide bandwidth piezoelectric energy harvesting

Here, we present an ultra wide-bandwidth energy harvester by exploiting the nonlinear stiffness of a doubly clamped microelectromechanical systems (MEMSs) resonator. The stretching strain in a doubly clamped beam shows a nonlinear stiffness, which provides a passive feedback and results in amplitude-stiffened Duffing mode resonance. This design has been fabricated into a compact MEMS device, which is about the size of a US quarter coin. Based on the open circuit voltage measurement, it is expected to have more than one order of magnitude improvement in both bandwidth (more than 20% of the peak frequency) and power density (up to 2 W/cm 3 ) in comparison to the devices previously reported.