Poly(vinyl alcohol)/Gelatin-Based Eutectogels for the Sensitive Strain Sensor with Recyclability and Multienvironmental Suitability

Flexible gel-based strain sensors have made remarkable progress, emerging as promising candidates for wearable electronic devices. Too much attention was paid to the sensing sensitivity of the conventional gel sensors, and their environmental tolerance and green recyclability were ignored. This work designs a high ion conductive, multienvironmentally adaptable, and recyclable eutectogel, with gelatin-strengthened poly(vinyl alcohol) (PVA) and deep eutectic solvent (DES) as the gelator and disperser, respectively. Interestingly, the cross-linked network composed of PVA and gelatin polymer molecules endows the eutectogel with an ultimate tensile strength of 6.8 MPa. Moreover, the ionic liquid-like characteristic of DES at room temperature and abundant hydrogen bonds in DES can simultaneously improve the ionic conductivity (0.12 S/m) and environmental tolerance of the eutectogel. A reliable strain sensor based on this eutectogel exhibits high stability over a wide temperature range (-20 similar to 100 degrees C) and harsh chemical environments (acid and base). Furthermore, this recyclable eutectogel can be easily disintegrated and regelatinized via a simple solvation-evaporation procedure, while retaining its initial mechanical and sensing performances. This study creates a candidate for applications in wearable electronic devices and sheds light on minimizing the environmental impact of other electronic wastes.

Automated summary

Flexible gel-based strain sensors have shown promising potential for wearable electronic devices. However, conventional gel sensors have focused too much on sensing sensitivity while neglecting environmental tolerance and recyclability. This study presents a high ion conductive, environmentally adaptable, and recyclable eutectogel that exhibits excellent mechanical properties and environmental stability. The findings provide insights into minimizing the environmental impact of electronic waste.