Metal mesh embedded in colorless shape memory polyimide for flexible transparent electric-heater and actuators

The current electroactive shape memory polymer composites (SMPCs) show low electric heating efficiency, and the transparency of the matrix is seriously damaged by the conductive fillers. In this work, transparent metal mesh is used to replace the conductive fillers to construct a conductive network for electrical actuation for the first time. The self-cracking aluminum mesh is embedded in the transparent shape memory polyimide film (Alm@TSMPI) by solution casting. As a new type of flexible and transparent heater, the Alm@TSMPI has advantages of fast response and high steady-state temperature. As an electric actuator, the Alm@TSMPI is active and deformable depending on its variable stiffness characteristics, and reverts to its original shape within 13 s under electric stimulation. This is the first report on an electroactive transparent shape memory polymer while maintaining light transmission. Moreover, the transition temperature of 230 °C is much higher than that of all other reported electroactive SMPCs. Furthermore, the Alm@TSMPI is attached to transparent shape memory polystyrene as a flexible transparent heater, and the deformation is triggered by electric field. According to this strategy, the Alm@TSMPI can be applied for the electrical actuation of other SMPs, extending the applications in the electric actuators.