A compliant mechanism based piezoelectric beam energy harvester with multi-mode frequency up conversion

Various piezoelectric beam based approaches have been well studied to support vibrational energy harvesting, where the natural frequency of the energy harvester is purposely designed to match the external vibrations. Note that the external vibrations usually exhibit a low frequency nature, which significantly limits the output of piezoelectric beam based energy conversion because the operational frequency for such systems is much higher. In this work, we propose a novel compliant mechanism based energy harvester combining the piezoelectric beam structure with a multi-stable compliant mechanism, which is capable of harvesting vibrational energy with multiple frequency up conversion modes to improve the efficiency of such systems. The proposed design is developed and analyzed from electro-mechanical perspective. A prototype of the proposed method is designed and comprehensively evaluated in various experiments to verify the performance and effectiveness of the piezoelectric energy harvester.