Sensing-actuation system with zero signal delay for ultrasensitive recognition

Ionic actuators, which convert external stimuli into mechanical deformation, have garnered significant attention in flexible electronics and soft robotics. It is crucial to integrate sensing capabilities into actuators so as to meet the growing demand for real-time feedback in complex scenarios. However, existing sensing-actuation systems rely on external sensors, leading to redundancy, large response delays and low integration. Here, we develop a sensing-actuation system directly integrating ionic actuator and piezoresistive sensor together with simple structure, fast response and high stability. The as-designed system combines rapid ion migration inside device and dynamic reconstruction of conductive network under strain, and realizes actuating and sensing functions simultaneously. It is revealed that the sensing-actuation system eliminates signal response delay of traditional system as long as 250 ms, which is even comparable to adult reaction speed of 300 ms. The system delivers superior actuating and sensing properties with high stability over 1000 cycles in air condition, and is further utilized to detect various human activities and physiological signals. Our study provides an advanced sensing-actuation system with prompt response and high integration for soft robotics and wearable electronics.