Composites of aligned (K,Na,Li)NbO3 (KNLN) piezoceramic particles in a PDMS polymer matrix are presented as promising materials for flexible sensors and energy harvesters. Their ease of processing is matched with a relatively high damage tolerance and piezoelectric performance at low dielectric loss. To maximize piezoelectric performance, the effective poling conditions for dielectrophoretically structured KNLN-PDMS composites are studied, and compared with random composites. Effective poling is identified at 7.5 kV/mm, for 6 min at 150°C in structured composites. The structured composites demonstrate improved piezoelectric performance, with respect to random composites, while retaining the low stiffness of the PDMS polymer matrix.
- Piezoelectric composites