Pencil‐Drawn Generator Built‐in Actuator for Integrated Self‐Powered/Visual Dual‐Mode Sensing Functions and Rewritable Display

Multifunctionality is important to the development of next‐generation actuators and intelligent robots. However, current multi‐functional actuating systems are achieved based on the integration of diverse functional units with complex design, especially lacking in multi‐mode sensing and displaying functions. Herein, a light‐driven actuator integrated with self‐powered/visual dual‐mode sensing functions and rewritable display function is proposed. The actuator demonstrates a bending curvature of 0.93 cm(−1) under near‐infrared light irradiation. Meanwhile, by embedding a pencil‐drawn graphite generator and thermochromic materials, the actuator also provides two independent sensing functions. First, owing to the photo‐thermoelectric effect of graphite, the actuator spontaneously outputs a self‐powered voltage (Seebeck coefficient: 23 µV K(−1)), which can reflect the deformation trend of actuator. Second, color changes occur on the actuator during deformation, which provide a visual sensing due to the thermochromic property. Furthermore, the actuator can be utilized as a rewritable display, owing to the integrated color‐memorizing component. Intelligent robots, switches, and smart homes are further demonstrated as applications. All of them can spontaneously provide self‐powered and visual sensing signals to demonstrate the working states of actuating systems, accompanied by rewritable displays on the actuators. This study will open a new direction for self‐powered devices, multi‐functional actuators, and intelligent robots.