Development of wide-band low-frequency MEMS vibration energy harvester for utility infrastructure core monitoring system

An aluminum-nitride (AlN) based energy-harvesting MEMS sensor is developed. We aimed at realizing energy-harvesting sensor with functional feature of wide-band response at low-frequency vibration domain, owing to the high-power density of vibration sources energy in a particular low frequency with several Hz deviations. By simplifying and analyzing the vibration module of the sensor structure, a special design was implemented for the first time. The given wide-band vibration energy-harvesting sensor has a disk proof mass attached to three sandwiched-AlN spring-system flexures. By MEMS techniques, the given sensors were fabricated well with the single die size of 7×7 mm and observed by the scanning electron microscopy (SEM) comprehensively. The functional feature of electrical performance of the energy-harvesting sensor was evaluated. The results demonstrated that a low resonant frequency of 57 Hz at central with wide band of 10 Hz and the voltage output of 2.5–4 mV at acceleration of 0.1–0.6g can be typically achieved. We look forward the low-frequency vibration sensor with wide-band response function can be used for many industrial and civilian applications to eliminate the restriction on power source.