Photothermal regulated multi-perceptive poly(ionic liquids) hydrogel sensor for bioelectronics

Hydrogels with excellent flexibility, water retention, and biocompatibility are natural carriers for drug delivery. However, the poor drug compatibility seriously limits the practical application of traditional PNIPAM-based hydrogel. Herein, a photothermal regulated smart hydrogel was synthesized by introducing poly(ionic liquids) chain into the binary polymer chain. The temperature-induced hydrophilic-hydrophobic switchable poly(ionic liquids) chain endows the smart hydrogel with editable transparency, enabling intuitive visualization of drug loading and releasing capacity. The smart hydrogel could be used as NIR/temperature-controlled drug carrier to achieve efficient and visualized release (40.8 % drug release rate in 30 min). Besides, the smart hydrogel sensor showed excellent strain sensing sensitivity (gauge factor = 3.73), short response time (116 ms), high durability (1800 s at 20 % strain), and impressive temperature sensing sensitivity (TCR = -1.252 %/°C). Based on the excellent sensing performance and editable drug-delivery ability, the smart hydrogel was assembled into a dynamic wound management system to realize personalized wound treatment and wireless state diagnosis. The wireless sensor early warning system could realize wireless monitoring and state warning of joints (fingers, ankles, and elbows), exhibiting guiding significance for rehabilitation treatment. Moreover, the high-resolution sensor array composed of 5 × 5 smart hydrogels could accurately identify the strain, temperature and NIR light in three-dimensional space and direction. In short, the smart hydrogel provides an innovative solution to personalized wound diagnosis and assisted rehabilitation.