MEMS Vibration Energy Harvesting Devices With Passive Resonance Frequency Adaptation Capability

Further advancement of ambient mechanical vibration energy harvesting depends on finding a simple yet efficient method of tuning the resonance frequency of the harvester to match the one dominant in the environment. We propose an innovative approach to achieve a completely passive, wideband adaptive system by employing mechanical nonlinear strain stiffening. We present analytical analysis of the underlying idea as well as experimental results obtained with custom fabricated MEMS devices. Nonlinear behavior is obtained through high built-in stresses between layers in these devices. We report experimentally verified frequency adaptability of over 36% for a clamped-clamped beam device at 2 g input acceleration. We believe that the proposed solution is perfectly suited for autonomous industrial machinery surveillance systems, where high amplitude vibrations that are necessary for enabling this solution, are abundant.