Advanced design for electrochemically flexible iontronic tactile sensing

Abstract Electrochemically flexible iontronic tactile sensing (EFITS) has emerged as a promising technology in artificial touch, alleviating inherent limitations of traditional electronic sensors by emulating the ion-driven electrochemical transduction of biological skins. Enabled by advances in electrochemistry, materials science, structural design, interfacial engineering, advanced manufacturing, and artificial intelligence, EFITS can convert mechanical stimuli into electrochemical signals, featuring high sensitivity over wide pressure range, low limit of detection, reliable long-term operation, and intelligent recognition. With electrochemical double-layer capacitive iontronic tactile sensing emerged, pseudocapacitive and battery-type devices have shown promising developments in EFITS. However, a systematic overview of advanced EFITS remains lacking. Herein, we comprehensively review the latest advancements in EFITS. Beginning with the electrochemical tactile sensing principles, we critically summarize progress in composite materials, device architectures, and micro-nano interfaces, followed by an examination of fabrication strategies. We further carry out a statistical comparison of key performance metrics to enable quantitative benchmarking across high-performance EFITS devices and highlight representative applications in healthcare, environmental monitoring, human-machine interaction, and intelligent robotics. Finally, we discuss interdisciplinary challenges and outline possible pathways toward fully adaptive, intelligent, and durable EFITS, aiming to provide a consolidated understanding and guidance for future research. Graphical Abstract Inspired by electrochemical processes in biotactile perception, electrochemically flexible iontronic tactile sensing (EFITS), which synergistically employs ions and electrons, has attracted growing interest. This article comprehensively reviews recent advances in EFITS mechanisms, composite materials, architectures, micro-nano interfaces, fabrications, applications, and performance, especially with artificial intelligence, as well as discusses current challenges along with potential solutions to support future research