High Linearity, Low Hysteresis Ti₃C₂T_x MXene/AgNW/Liquid Metal Self-Healing Strain Sensor Modulated by Dynamic Disulfide and Hydrogen Bonds

Flexible wearable strain sensors have received extensive attention in human–computer interaction, soft robotics, and human health monitoring. Despite significant efforts in developing stretchable electronic materials and structures, developing flexible strain sensors with stable interfaces and low hysteresis remains a challenge. Herein, Ti₃C₂T_x MXene/AgNWs/liquid metal strain sensors (MAL strain sensor) with self-healing function are developed by exploiting the strong interactions between Ti₃C₂T_x MXene/AgNWs/LM and the disulfide and hydrogen bonds inside the self-healing poly(dimethylsiloxane) elastomers. AgNWs lap the Ti₃C₂T_x MXene sheets, and the LM acts as a bridge to increase the lap between Ti₃C₂T_x MXene and AgNWs, thereby improving the interface interaction between them and reducing hysteresis. The MAL strain sensor can simultaneously achieve high sensitivity (gauge factor for up to 3.22), high linearity (R² = 0.98157), a wide range of detection (e.g., 1%–300%), a fast response time (145 ms), excellent repeatability, and stability.In addition, the MAL strain sensor before and after self-healing is combined with a small fish and an electrothermally driven soft robot, respectively, allowing real-time monitoring of the swinging tail of the small fish and the crawling of the soft robot by resistance changes.