Programmable, UV-Printable Dielectric Elastomers Actuate at Low Voltage without Prestretch and Supporting Frames
mediaposted on 04.12.2020, 15:07 by Ramadan Borayek, Pengpeng Zhang, Habimana J. Willy, Mostafa Zedan, Jian Zhu, Jun Ding
Dielectric elastomers are soft and perfect insulator polymers able to produce large strains with high energy density under the effect of applied high voltage. However, their use in practical applications is hindered by the need for high voltage to actuate. Also, they need prestretching between rigid frames to produce out-of-plane shape changes, which may reduce their lifetime. Here, we synthesized a set of elastomers with high permittivity (from 20 to reach 60 at 103 Hz), controllable thermal properties (Tg vary from −15 to −50 °C), and good mechanical properties (Young’s modulus values between 0.48 and 0.2 MPa at 20% strain). Due to the high permittivity, an actuator made of the material was able to respond to a low voltage of 700 V and produce a 6.5% area strain for more than 10 000 cycles. Moreover, the elastomers were found to produce giant free-end bending displacements with prespecified bending direction (bend to the side of the positive electrode) under a low electric field, which we called programmable dielectric elastomers (PDE). Besides the aforementioned characteristics and performance, the formulated elastomers are suitable for UV-based three-dimensional (3D) printing. The printability of the elastomers allows fabricating programmable complex geometries to produce high deformations under relatively low electric fields.