Bioinspired Ultratough and Rapidly Responsive Hydrogels Empower Silent Communication

The development of sustainable flexible electronics is hindered by a lack of sensing materials that synergize eco‐friendliness, robust mechanical properties, and reliable electromechanical responsiveness. While starch‐based hydrogels present a promising sustainable alternative, their widespread application is limited by inherent brittleness and significant signal hysteresis. Here, a molecular engineering strategy is proposed to address these limitations. Porous starch is first obtained through a gradual solvent exchange process to enhance chain accessibility. Protocatechuic acid (PCA) is then covalently grafted onto the starch backbone via EDC/NHS‐mediated esterification, introducing dynamic hydrogen‐bonding and π − π interaction motifs. By optimizing the ratio between PCA‐modified starch and polyacrylamide (PAM), a bioinspired hydrogel with exceptional toughness and rapid electromechanical response is achieved. The resultant hydrogel exhibited pronounced strain‐dependent resistance behavior, enabling its integration into a wireless wearable human‐machine interface. To ensure robust decoding against motion‐induced noise, a finite state machine (FSM)‐based algorithm is employed for adaptive signal segmentation, achieving a character‐level accuracy of 99.2% in trials with healthy subjects ( n = 10). This work not only introduces a high‐performance, sustainable hydrogel platform but also demonstrates a practical route toward inclusive and language‐independent human‐machine communication.