Smart Sand-a wide bandwidth vibration energy harvesting platform

Abstract

We propose a concept for true wide bandwidth vibration energy harvesting. Our approach exploits nonlinear stretching of fixed-fixed beams in an off-resonance mode, effectively expanding the operational frequency range well beyond the narrow bandwidth of linear resonators. Our initial prototype demonstrates operation between 160-400 Hz, without the need for frequency tuning. A simple dynamic model shows good agreement with measurements. Optimized device geometry will allow for even lower frequency operation (starting at 60 Hz) at strain levels above 1e-3 (ideal for piezoelectric transduction). © 2009 American Institute of Physics.