Generating characteristics of a theta-type piezoelectric energy harvester

A theta-type piezoelectric energy harvester was proposed to increase the power generated by energy harvesters. The generating device consists of a rectangular piezoelectric ceramic plate and two hat-shaped elastic bodies. Both ends of the ceramic were clamped by the two elastic bodies at the upper and the bottom sides of the ceramic, and this structure converted vertical vibration or pressure on the device to a horizontal extension of the ceramic plate. This structure also lessens the stress of the ceramic because it can protect against direct pressure being applied to the ceramic. The theta-type generating device can generate electrical power by using the lower frequency vibrations that can be found easily in our lives. The generating characteristics of the piezoelectric harvester depended on the length and the width of the ceramic and were determined by using a finite-element-method program.