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 198 μW when excited with a peak acceleration of 0.2 g (where 1 g is 9.8 m/s2) at 35 Hz. The output power remains higher than half of the maximum power (99 μW) for the frequency band from 34.4 to 42 Hz, 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 20 μW from 29.5 to 48 Hz, achieving a 20-μW fractional bandwidth of 48%. This is the highest reported fractional bandwidth for this low 0.2 g 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 434 MHz on–off-keying wireless transmitter while the electronics are used as the inertial distributed mass.