An energy harvester powered wireless accelerometer for rotorcraft HUMS is described. Design strategies are presented for optimally addressing the competing demands of robustness, sensor capability, and weight. The resulting 1.25 cubic inch sensor and harvester is capable of wirelessly streaming 3.2 kHz vibration data at low vibration levels. This solution is based on a highly flexible wireless protocol exhibiting high throughput, rapid response, and ultra-low power consumption. The harvester delivers 6.4 mW of continuous power to the sensor for 1.0-g vibration at 700 Hz. The high power density vibration and tiiermal energy harvester solutions offer full sensor functionality down to vibration levels of 125-mg and air to surface temperature differences of 12°C, respectively.