Soft actuators based on piezoelectric composites for nanoscale self-bending

Nano/microscale objects would be far less damaged by soft actuators than rigid actuators in the mechanical nano/micromanipulation, but the precision of most soft actuators cannot meet the requirements. In this work, a kind of soft actuators which can realize nanoscale self-bending are developed on the basis of lead zirconate titanate (PZT)/shape memory polyurethane (SMPU) composites. The self-bending ability is the result of the weak polarization electric fields produced by the combination of the microstructures of particulate composites and the fringe effect of electric fields. However, unlike common piezoelectric actuators, strong polarization electric fields would weaken the actuation ability (self-bending ability). The PZT/SMPU actuators are able to generate nanoscale self-bending displacements with the maximum error of +/- 8 nm in a common condition without controlling any environmental parameter. This work provides a helpful reference for the design of soft self-bending actuators based on piezoelectric particulate composites.