Introducing an extremely high output power and high temperature piezoelectric bimorph energy harvester technology based on the ferroelectric system Bi(Me)O₃-PbTiO₃

Here, we outline the material selection and design of a novel bimorph piezoelectric energy harvester with an extremely high energy harvesting output power density of over 8 mW/g2 cm3 up to 250 °C. With optimized mass loading, the performance can achieve five times higher output power density from 5.64 to 29.77 mW/g2 cm3, with reduced frequencies of 580-69 Hz in loading tip masses of 0.8 and 30 g, respectively. The novel harvesters were fabricated utilizing (1-x)BiScO3-xPbTiO3 piezoceramic composition and designed to achieve the maximum figure of merit (d33 × g33), which was 15.5 × 10-12 m2/N when x = 64%. The harvester remains operational even at temperatures above 250 °C but demonstrates a systematic falloff of the high performance values with power densities of 8.7, 5.4, and 1.4 mW/g2 cm3 at 250, 300, and 350 °C, respectively. It should be noted that these performance numbers are still high compared to previous reports in the literature. The focus was then to improve the bonding/interface and dimensions that minimize clamping and depoling conditions in order to optimize the overall harvester design. We systematically outline the design considerations for room temperature and high temperature performance. Hence, we introduce a guideline for a novel bimorph harvester to provide significantly increased output power levels (mW) for higher temperature applications.