Axe-Head-Shaped Piezoelectric Energy Harvesters Designed for Base and Tip Excitation-Based Energy Scavenging

In this article, polyvinylidene fluoride (PVDF) ferroelectric polymer thin-film-based two axe-head-shaped cantilever-type piezoelectric energy harvester (C-PEH) devices are presented, such as Device 1.1 with ring proof mass and Device 2.1 without ring proof mass for base excitation and tip excitation-based energy harvesting, respectively. These fabricated miniature axe-head-shaped C-PEHs comprising different active areas and volumes are evaluated by both finite-element method (FEM) -based simulations and experimentations. We also present a concept to use these prototypes in a wireless mouse to harvest base and tip excitation-based energy. Device 1.1 made with 96.5-mm3 active volume including an axe-head-shaped C-PEH and 0.72-g ring proof mass produces maximum 7.81- and 594.5-nW power outputs when it was excited by the {x} -axis (direction of normal wireless mouse sliding) and {z} -axis (direction of gravity entailing 0.5-g acceleration) -based vibrations, respectively. Device 2.1 made with 14.8-mm3 active volume comprising only an axe-head-shaped C-PEH produces maximum 9.3391- and 0.0369- \mu \text{W} power outputs when it was excited by a rotary motion due to wireless mouse-wheel rotation and {z} -axis (direction of gravity entailing 0.5-g acceleration) -based vibration, respectively. The experimental results demonstrate excellent performance when compared to the test results of the well-known same active area and volume-based trapezoidal-shaped C-PEHs and other already published similar devices.