MEMS Energy Harvesting from Low-frequency and Low-g Vibrations

Abstract

MEMS vibration energy harvesting has been investigated to provide energy to low-power micro-electronic systems and potentially to enable batteryless autonomous systems. While enjoying the small footprint hence the ability to be embedded in other systems, MEMS vibration energy harvesters are working at much higher frequencies and input vibration amplitudes. The mechanical resonator based energy harvesters seem inherently have such high frequency due to the scaling of the device dimension. Lower the working frequency range and input vibration amplitude are possible by optimizing the dimensions of the device. However, we are viewing the problem from a different perspective and proposing a solution based on employing the common material property of the micro-fabricated thin film – residual stress. We found that by taking advantage of the compressive residual stress, a bi-stable mechanical resonator could be built and a new spectrum of dynamics can be brought into energy harvesting, which could lower the working frequency range and input g value. The concepts have been analytically simulated and experimentally verified by a meso-scale model.