The electric field, dc bias voltage and frequency dependence of actuation performance of piezoelectric fiber composites

•A free strain of 1900 microstrain was achieved in PFCs.•Decreased excitation frequency significantly enhanced PFCs’ free strain performance.•PFCs’ actuation performances were enhanced with the increase of voltage amplitude and the decrease of dc bias voltage.

The free strain performance of piezoelectric fiber composites (PFCs) and the PFCs’ capability of actuating a cantilever exhibited strong dependence on the excitation voltage, e.g., the voltage amplitude, dc bias voltage and frequency. The enhanced free strain performance was observed when a large voltage amplitude and low dc bias voltage were applied, owning to the increase of d33 piezoelectric coefficient. The PFCs showed better free strain performance under the quasi-static condition than dynamic conditions due to the frequency dependence of d33 piezoelectric coefficient. The influence of voltage amplitude and dc bias voltage on the actuation capability was similar to that on the free strain performance. However, for the customized cantilever structure, the first bending resonance existed definitely at around 25 Hz, which indicated that the mechanical effect was the key factor influencing the actuation performance at measured frequency range of 0.1–35 Hz.