Flexible PTFE/MXene/PI soft electrothermal actuator with electromagnetic-interference shielding property

Abstract In recent years, soft electrothermal actuators (ETAs) have attracted great concern because of their potential applications in biomimetic intelligent devices, soft robotics and aerospace engineering. However, achieving the simultaneous optimization of low-voltage actuation, ultrafast preparation and highly integrated functionality are main challenges to the development of ETAs. Herein, a flexible, hydrophobic, mechanically robust and electromagnetic-interference (EMI) shielding PTFE/MXene/PI soft ETA is constructed through a very simple and fast “cutting and sticking” method by taping PTFE and PI tapes onto the surface of MXene film. The commercially available PTFE and PI tapes endow PTFE/MXene/PI sandwich structure with ideal mechanically robustness and hydrophobic self-cleaning function, thus it can work in different environments. Remarkably, PTFE/MXene/PI sandwich structure shows an outstanding EMI shielding ability with the maximum SET value of 44 dB owing to the high electrical conductivity of MXene film. More importantly, the PTFE/MXene/PI sandwich actuator can bend from PTFE side toward PI side under the electrical stimulus, because the excellent electrothermal MXene layer is sandwiched between the two tapes with large difference in thermal expansion coefficients. Under a 6 V low voltage, the actuator can generate heat energy with the maximum saturation temperature of 110 °C and large bending deformation with the maximum bending angle of 122° within 40 s. Interestingly, the PTFE/MXene/PI structure can be designed and manufactured in different shapes and configurations upon actuation, such as the “S” shape and four-finger gripper. At last, a smart shielding curtain with the combination of actuation properties and EMI shielding performance is finally developed as a principle of concept, which further indicates the multifunctional PTFE/MXene/PI ETA can be widely applied in smart EMI shielding system and soft robotic devices.