Highly Flexible, Self-Healing, Adhesive, Conductive and Temperature-Resistant Eutectogels Via a One-Step Co-Crosslinking Method for Real-Time Wearable Sensors

Abstract

Developing smart hydrogel that possess a combination attribute such as low-cost, biocompatibility, superior stretchability, toughness, ionic conductivity, self-healing, interfacial adhesion, and high sensitivity over a broad temperature range through a straightforward method, remains a significant challenge. We address this by introducing a one-step co-crosslinking strategy that forms a multi-crosslinking network, integrating covalent bonds with reversible hydrogen-bond networks between dual monomers and deep eutectic solvents. This approach bestows the transparent hydrogel with a balance of high-performance and multifunctional attributes, including strong adhesiveness, inherent self-healing abilities, improved electrical conductivity, and versatile mechanical performance. Notably, these hydrogels demonstrate impressive fracture strength (68.21 MPa), a high Young's modulus (1659.36 MPa), and remarkable toughness (58.48 MJ m-3), along with an extensive stretchability range from 10% to 4000%. Moreover, they retain their mechanical flexibility and electrical conductivity across a wide temperature range, extending from sub-zero temperatures down to -80°C to elevated temperatures up to 60°C. As a proof-to-concept, the approach provides an alternative insight for the potential versatile applications in flexible electronics and biomedical devices.

Keywords: Eutectogels, Self-adhesive, Conductivity