Enhanced acceleration transmission via dual-beam frequency conversion interposer for design-flexible MEMS vibration energy harvesters

An interposer with a bistable structure and no internal stress can convert random environmental vibrations and efficiently transmit vibrational energy to micro-electromechanical systems vibrational energy harvesters (MEMS VEHs). However, with conventional methods, the MEMS VEH must be designed to match the interposer, significantly limiting its design flexibility. This study presents an extended approach for broadening the recovery vibration bandwidth and efficiently transmitting acceleration to a MEMS VEH using a dual-beam frequency conversion interposer (dual-beam-FCI). The MEMS VEH receives large acceleration induced by a snap-through (ST) of a bistable beam. A comparison between the theoretically calculated energy required for ST and the energy input during the vibration experiments revealed that ST occurred with less energy than that theoretically calculated, regardless of the input frequency, i.e., even at low input frequencies of approximately 10–20 Hz. Therefore, the dual-beam-FCI, which can be integrated into various MEMS VEHs, is useful for broadening the recovery bandwidth and efficiently harvesting low-frequency vibrational energy, particularly in the range of 10–20 Hz. The dual-beam-FCI can generate large accelerations via ST without imposing design limitations on the integrated MEMS VEH and thus shows applications for environmental energy harvesting using various MEMS VEHs.