Packaging strategy for maximizing the performance of a screen printed piezoelectric energy harvester

This paper reports the extended design and simulation of a screen printed piezoelectric energy harvester. The proposed design was based on a previous credit card sized smart tag sensor node, and packages the power conditioning circuit in the free space above the tungsten proof mass layer. This approach enables electronic components to be mounted onto the cantilever beam. These are used to provide additional weight at the tip of the cantilever structure. The design structure contains a T-shape cantilever beam with size of 47 mm x 30 mm x 0.85 mm which is fabricated using screen printing. The original smart tag energy harvester has been tuned to have a resonant frequency around 67.4 Hz at which it obtains a RMS Voltage of 5.2 V in open-circuit condition and 243.3 μW. ANSYS simulation results predict the revised architecture can generate 421.9 μW approximately twice of the RMS power produced by the original design along with a higher open-circuit RMS Voltage of 8.0 V. The resonant frequency is dropped to 53.4 Hz.