Versatile Eutectogel Sensor With Tunable Mechanical Properties for Monitoring of Human Bioelectromechanical Signals

Further development of wearable and implantable devices is constrained by the adaptive limitations of flexible gels sensors, which require robust mechanical properties, high electrical conductivity, strain sensitivity, and biocompatibility. Compared to traditional conductive gels, eutectogels based on deep eutectic solvents (DES) offer a safe, economical, environmentally friendly, and easily scalable alternative. Here, we report a green economic strategy to fabricate two multifunctional conductive gels with tunable mechanical and electrical properties and multifunction from polyvinyl alcohol (PVA) and DES (PD). By varying the component ratio and preparation methods, we precisely regulate the PD's mechanical and conductive properties while introducing antibacterial and biocompatibility functions, significantly broadening its application scope. The obtained PD gel exhibits excellent biosafety and antibacterial properties, alongside an exceptionally broad mechanical range, with Young's modulus ranging from 0.84 to 10.22 MPa and a maximum elongation of 718%. It demonstrated sensitive strain sensing (GF = 2.05) and a favorable anti-freezing ability (-10°C). The Young's modulus of PD Hydrogel ranges from 4.26 to 1.98 kPa. It illustrated outstanding efficacy in replacing commercially available electrocardiogram (ECG) electrode gels, joint deformation, and temperature and humidity monitoring sensors. This simple, additive-free, and environmentally friendly PD eutectogel offers significant application potential in next-generation health monitoring.