Design and characterisation of a piezoelectric scavenging device with multiple resonant frequencies

This paper reports design and characterisation of a new piezoelectric scavenging device that has multiple resonant frequencies in the low frequency range. The structure is constructed with the most accessible off-the-shelf piezoelectric cantilevers. The device has been characterised using both self-excitation and a customised shaker table. Power conditioning circuits for the scavenging device have been designed and analysed. The experimental results show that the 9-beam structure has at least 7 resonant peaks from frequency range of 100 Hz to 1000 Hz. A maximum DC voltage of 3.58 V has been measured subject to 130 Hz external vibration. Experiments show that the output power of the device depends on the load resistance, it is measured that the output power of the 9-beam structure is around 20.5 μW with a 10 kΩ resistor.