Wide-bandwidth, meandering vibration energy harvester with distributed circuit board inertial mass

A wide-bandwidth, meandering piezoelectric vibration energy harvester is presented for the first time utilizing the sensor node electronics as a distributed inertial mass. The energy harvester achieves an experimental maximum power output of 198μW when excited with a peak acceleration of 0.2g (where 1g is 9.8m/s2) at 35Hz. The output power remains higher than half of the maximum power (99μW) for the frequency band from 34.4 to 42Hz, achieving a half-power fractional bandwidth of 19.9%, an increase of 4× compared to typical single-mode energy harvesters. The output power remains above 20μW from 29.5 to 48Hz, achieving a 20-μW fractional bandwidth of 48%. This is the highest reported fractional bandwidth for this low 0.2g acceleration level. The distributed inertial mass in combination with the meandering harvester's close natural frequency spacing is what enables the wide bandwidth. The energy harvester is demonstrated to autonomously operate a sensor node to sense and transmit temperature through a 434MHz on–off-keying wireless transmitter while the electronics are used as the inertial distributed mass.