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

Abstract

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.

Electro‐Driven, Predefined Carbon Nanotube‐Based Phase Change Composite as a Lifting‐Jack

“…For current stimuli-responsive shape memory materials, the primary actuation pattern associated with external work is the stretching and contracting motion in the length direction, enabling vertical lifting of heavy objects. [17,47] In contrast, the jacking motion accompanied by a convex, bent, or Ω-shape, [24,26,46,[48][49][50][51] is a unique locomotion mode that has been less studied, yet is of significant importance in fields such as soft robotics. [51] Recently, several approaches have been exploited to achieve macroscopic curvature changes, including the modulation of magnetic torque distribution in magnetic composites, [49,51] control of charge interaction and directional migration in dielectric elastomers or IPMCs, [19,52] regulation of thermal expansion behavior of carbon nanomaterials [25] or the mismatch of thermal expansion coefficient with polymers, [24,26] as well as the differential swelling behavior in gradient or multilayer structural materials, [4,7,53] etc.…”

“…Polymer-based shape change materials or actuators have advantages, such as lightweight, high flexibility, and low cost, with tremendous application prospects in artificial muscles, [1,2] soft DOI: 10.1002/adfm.202308677 robots, [3,4] electrical control, [5] environmental exploration [6] and intelligent sensors [7,8] and wearables. [9,10] To this end, several categories of functional polymers and polymer-based composites have been developed in terms of molecular design [11,12] and microstructural regulation, [13] including: 1) shape memory polymers [14,15] and liquid crystal elastomers [16][17][18] based on interactions and alignment-isotropy transition of molecular chains, 2) dielectric elastomers [19,20] or ionic polymermetal composites (IPMCs) [21] based on electrostatic repulsion/solvated ions migration, 3) composites with multilayer or gradient structures [22][23][24][25][26] relying on the differences in thermal expansion coefficients or swelling behaviors, and 4) phase change material (PCMs) filled polymer-based composites relying on volume expansion/contraction, [27,28] regulation of crystallization behavior and mechanical properties [15] or segmental fixation/release effect [13,29,30] of solid-liquid phase transition process. However, most of the above strategies rely on light-or heatdriven modes and produce unsatisfactory performance.…”

Multi‐Functional Actuators Made with Biomass‐Based Graphene‐Polymer Films for Intelligent Gesture Recognition and Multi‐Mode Self‐Powered Sensing

“…Several researchers have combined PTEG in situ on photo-thermal actuators to prepare flexible photo-thermal actuators with self-powered sensing functions. [19][20][21] For example, Chen et al prepared a graphite/paper/thermochromic dye photothermal material by the pencil-on-paper method and applied it to a light-driven actuator with an integrated self-powered/visual dual-mode sensing function and rewritable display function. [19] Weng et al proposed a Ti 3 C 2 T X -based composite modified by bamboo nanofibers, based on which a light/electro-driven actuator was developed to accomplish Marangoni floating and selfpowered temperature sensing.…”

“…[19][20][21] For example, Chen et al prepared a graphite/paper/thermochromic dye photothermal material by the pencil-on-paper method and applied it to a light-driven actuator with an integrated self-powered/visual dual-mode sensing function and rewritable display function. [19] Weng et al proposed a Ti 3 C 2 T X -based composite modified by bamboo nanofibers, based on which a light/electro-driven actuator was developed to accomplish Marangoni floating and selfpowered temperature sensing. [21] Benefiting from the wireless actuation characteristics of the light source, the entire energy conversion process can be easily controlled without external force.…”

“…Several researchers have combined PTEG in situ on photo‐thermal actuators to prepare flexible photo‐thermal actuators with self‐powered sensing functions. [ 19 , 20 , 21 ] For example, Chen et al. prepared a graphite/paper/thermochromic dye photo‐thermal material by the pencil‐on‐paper method and applied it to a light‐driven actuator with an integrated self‐powered/visual dual‐mode sensing function and rewritable display function.…”