Development of energy harvesting MEMS vibration device sensor with wideband response function in low-frequency domain

An aluminum-nitride (AlN) based microelectromechanical system (MEMS) vibration device sensor with a power-harvesting function is developed. We aimed at realizing a vibration sensor with wideband response in a low-frequency vibration domain, owing to the high-power density of vibration sources energy normally in a particular low frequency with several hertz deviations. A special design was implemented in this work, for the first time, to realize the sensor structure with a wideband response function. The given sensor has a disk-shaped proof mass attached to three sandwiched AlN spring flexures and a supporting beam system. Using MEMS techniques, the sensors were fabricated with the single die size of 7 x 7 mm and observed via scanning electron microscopy comprehensively. The functional feature of the electrical performance of the sensors was evaluated. The results demonstrated that with the given sensor, which has a low center resonant frequency of 57.5 Hz with a response feature of a half-voltage bandwidth of > 10 Hz, an output voltage of 2.4-4 mV at an acceleration of 0.1-0.6 g can be typically achieved. The low-frequency vibration sensor with a wideband response function can be used for many industrial and civilian applications to eliminate the restrictions on power sources.