Synergistic Enhancement of Hole–Bridge Structure and Molecular‐Crowding Effect in Multifunctional Eutectic Hydrogel Strain/Pressure Sensor for Personal Rehabilitation Training

Abstract Given the electrical signal transduction capability and excellent biocompatibility, conductive hydrogels are regarded as ideal candidates for high‐performance strain/pressure sensors applied in personalized medicine. However, there are challenges in concurrent attainment of flexible hydrogel‐based sensors with remarkable conductivity, sensitivity, and reliable stability. Herein, a synergistic strategy based on hole–bridge structure and molecular‐crowding effect is proposed to fabricate a multifunctional hydrogel‐based strain/pressure sensor. As‐prepared eutectic hydrogel displays comprehensive performances of impressive electrical conductivity (2.81 S m⁻¹), boosted mechanical robustness (a tensile strength of 2.95 MPa), and reliable environmental tolerance (≈79.8% water retention at 50 °C for 20 days; frost resistance = −45.3 °C). Notably, the eutectic hydrogel‐derived stretchable sensor with effective antibacterial ability exhibits enhanced sensitivity (gauge factor = 4.49) across a wide linear range, supporting the monitoring of joint movement and electrocardiographic signals, along with on‐demand photothermal treatment. As a demonstration, the employment of the hydrogel‐based stretchable sensor in efficiently conveying information and high‐fidelity handwriting recognition is investigated with the assistance of machine learning. This innovative eutectic hydrogel holds high promise for future applications as wearable‐smart devices integrated with wireless transmission modules, exhibiting great potential in personal rehabilitation training and healthcare monitoring.