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.