A Biomimetic Ionic Hydrogel Synapse for Self‐Powered Tactile‐Visual Fusion Perception

Abstract Living organisms with diverse perceptual functions interact with their environment through ion activity, a feature that bestows them with integrated processing, parallel operations, and efficient energy utilization. Inspired by this, an ionic hydrogel device is presented that seamlessly integrates multimodal sensing and synaptic properties, creating a simplified architecture for self‐powered tactile‐visual fusion perception. The precise control of ion transport through piezoionic and ionic thermodiffusion effects in the bilayer asymmetric hydrogel facilitates self‐driven multimodal sensing. The ionic relaxation effect, arising from differing mobilities between anions and cations, contributes to synaptic characteristics, including short‐term and long‐term plasticity. Consequently, this device alone constitutes a self‐powered tactile‐visual perception fusion system with signaling pathways similar to those of the skin and retina, endowing robotic arms with intelligent grasping capabilities and reflexive behaviors akin to human danger avoidance. Moreover, the device exhibits minimum pressure and light intensity detection limits of 3.6 KPa and 35.7 mW cm −2 , respectively, and operates without the need for an external power supply for information writing and reading, highlighting its practical applicability. This work offers valuable insights for developing neuronal sensing information integration devices facing humanoid robots and human‐robot interactions.