High performance PZT thick films based on bonding technique for d31 mode harvester with integrated proof mass

• The PZT thick film is fabricated based on bulk PZT bonding, grinding and polishing techniques.
• The vibration-based energy harvester with integrated silicon proof mass is developed to improve its output voltage and power.
• A simple model is created to calculate the conversion efficiency under different accelerations in the unit time.

A high performance piezoelectric PZT thick film for energy harvester with integrated silicon proof mass is proposed for scavenging energy from ambient vibration. This PZT film is fabricated based on low temperature bulk PZT bonding and thinning techniques. A lumped-parameter model of energy harvester is created to optimize the structural parameters of the device. The dimension of PZT, oxide and silicon layer composite cantilever is about 4000 μm × 1000 μm × 28 μm and the dimension of silicon mass is 2000 μm × 800 μm × 420 μm. When the matched loading impedance is 100 kΩ, the maximum output voltages of harvester at the acceleration of 0.5 g and 1 g are 3.4 V and 6.08 V, respectively. The maximum output powers at 0.5 g and 1 g are 20.2 and 57.6 μW, respectively. The energy conversion efficiency of this device is calculated as 38.15% and 26.9% at 0.5 g and 1 g, respectively.