High Performance, Nonlinear Piezoelectric MEMS Energy Harvesting from Low-threshold Mechanical Vibrations

The practical applications of nonlinear, wideband Mechanical Energy Harvesting (MEH) devices are often restricted due to their inability to generate useable electrical energy at very low ambient mechanical vibrations. This is even more challenging for the MEMS-scale devices due to several practical constraints. Here, we propose three different topologies of MEMS buckled beam structures which can be used for low-frequency, nonlinear bistable energy harvesting. The tapered beam structure shows minimum potential energy barrier height which lowers the minimum threshold of the external mechanical excitations for initiating large amplitude oscillations. As an alternative, a suitable electrical energy injection method is also demonstrated for this purpose. The final, optimized designs could lead to high-performance, MEH applications when incorporated with a piezoelectric transducer.