High output power density and strong vibration durability in a modified barbell-shaped energy harvester based on multilayer Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystals

Traditional piezoelectric energy harvesters are made of piezoelectric ceramics with a cantilever structure, which show a low output energy density. Thus, they are difficult to meet the requirements for self-powered electronics. Herein, we report a modified barbell-shaped piezoelectric energy harvester (BSPEH) based on two d33-mode cuboid Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 multilayer single crystal stacks (ten wafers with a thickness of 0.5 mm and d33 ∼ 1300 pC/N). Due to the electrically parallel and series connections of multilayer piezoelectric elements and the high figure-of-merit d33 × g33 of the single crystal, the maximum power density of BSPEH could reach 39.7 mW cm−3 (under an acceleration of 5 g), which is much higher than that of traditional cantilever piezoelectric energy harvesters (CPEHs), ∼0.1 mW cm−3. A maximum output voltage of 50.4 Vp–p was obtained when two crystal stacks are connected in series, and a maximum output current of 880 µA can be obtained when two crystal stacks are connected in parallel. Furthermore, the energy harvesting properties of BSPEH stay almost the same after 106 vibration cycles, while the properties of CPEH decrease 20% after 105 vibration cycles. This work indicates that BSPEH has a great potential in the application of wireless sensor networks for realizing the self-power of the equipment.