Porous ferroelectric materials have been evaluated for their piezoelectric energy harvesting capabilities. Macro-porous barium titanate (BaTiO3) ceramics were fabricated with a range of porosities using the burned out polymer spheres process. The pore fraction was tailored by mixing a pore forming agent with BaTiO3 powder in varying amounts by weight before cold-pressing and pressureless sintering. Introducing porosity into the ferroelectric significantly increased the energy harvesting figure of merit, with a maximum of 2.85pm2/N obtained at ∼40% relative density compared with ∼1.0 pm2/N for the dense material. The results demonstrate that introducing porosity into a piezoelectric potentially provides an effective route to improving the vibration energy harvesting capability of these materials.
- barium titanate
- Piezoelectric energy harvesting