A Bioinspired Ionic Diode Tactile Sensor for Embodied Sensorimotor Intelligence in Robotics

ABSTRACT The fusion of wearable sensors and embodied artificial intelligence (AI) is opening new pathways for human‐robotics interaction and personal care technologies. Biological skin relies on ion‐mediated tactile sensing while most artificial counterparts use electronic signal transduction, which creates a fundamental biointegration barrier. Here, we report a facile strategy for fabricating passive ionic diode tactile sensors as well as developing a novel fundamental understanding of the sensing mechanism, which combines semiconductor theory and charge‐induction effects. The device incorporates p‐ and n‐type ionic hydrogels separated by a nylon mesh with microchannels to form a bioinspired ionic diode. Under external pressure, the increased contact area between p‐ and n‐type ionic hydrogels enhances space charge generation, leading to charge accumulation in the electrical double layer, which produces measurable current signals. This design achieves outstanding sensing properties such as high sensitivity (1.71 kPa −1 ), fast response/recovery speed (0.2 s/0.2 s), excellent stability (>5000 cycles), and static/dynamic detection ability. Through integrating a sensor array with machine learning, accurate handwritten digit recognition (96% accuracy) has been realized. Furthermore, we attach a sensor array onto a robotic hand to recognize tracing motions during digit writing and respond with corresponding gestures mimicking human‐like context‐aware behavior.