High Curvature of Polymer-Based Miniaturized Flexible Actuator at Very Low Electric Field

The use of high electric fields, as well as pre-stressing, are the two main obstacles to the widespread use of poly(vinylidene fluoride (PVDF)-based actuators. In response, a new double-sided multilayer device has been developed which, coupled with a polarization procedure, enables high bending performance at low voltages. The actuator's symmetry allows zero bending at rest, while the high number of layers enables a strong field to be maintained while reducing the applied voltage. X-ray and permittivity studies reveal the ultimate links between the microscopic material displacement and the actuator deflection. These results, coupled with the analytical model developed in this work, demonstrate that the optimization of complex multilayer systems requires a detailed understanding of mechanics, design, and microstructure. Experimental, analytical and finite element results confirm that such a double-sided multilayer actuator is of 50% more efficient than a conventional single-sided actuator, up to 40 V mu m-1. These achievements open up new prospects for PVDF-based actuators in application of healthcare, such as arterial navigation. This work proposes a design and polarization routine that significantly improves the deflection of multilayer organic actuators, allows deflection in two directions and eliminates prestressing problems inherent in multilayer devices. Thanks to cost-effective and industrially scalable manufacturing process of devices, this new approach opens new possibilities of their integration in the fields of soft robotics and bio-medical. image