Investigation of mechanical energy harvesting cycles using ferroelectric/ ferroelastic switching

Piezoelectric energy harvesters have been widely developed in last decade due to their simplicity and practicality, but they suffer from low energy density. To increase the energy density, ferroelectric/ferroelastic switching could be an effective alternative energy harvesting approach. However, the nonlinearity and irreversibility of ferroelectric switching produces difficulty in establishing a stable working cycle. In this work, novel, practical and stable energy harvesting cycles using ferroelectric/ferroelastic switching are established and explored under quasi-static experimental conditions. A prototype device with a simple 'sandwich' configuration is tested. The results show that the cycle energy density can reach 11 mJ/cm3 under tensile loading and 3.2 mJ/ cm3 under compression, demonstrating great potential for practical applications.