Supertough, Healable, Self-Adhesive, and Antibacterial Eutectogels for Sensitive Strain Sensors

Abstract

Recently, eutectogels featuring the superiority of high ionic conductivity, good biocompatibility, and environmental stability have emerged as one of the most promising materials for fabricating flexible sensors. Nevertheless, the development of eutectogels with high toughness, self-healing, self-adhesion, and antibacterial properties simultaneously remains challenging. Herein, hydrophobic association eutectogels composed of poly(acrylic acid) (PAA) as the main polymer backbone, lauryl methacrylate/sodium dodecyl sulfate (LMA/SDS) as a micellar cross-linker, and choline chloride (ChCl)/protocatechuic acid (PCA)/water as the ternary deep eutectic solvent (t-DES) have been successfully synthesized. Owing to the reversible hydrophobic association and hydrogen bonding in gels, the eutectogels give an excellent toughness of 17.77 MJ/m³, an ultrahigh fracture strain of 4776%, and a desirable self-healing property. Furthermore, due to the incorporation of PCA with choline chloride (ChCl), the eutectogels demonstrate remarkable self-adhesion and antimicrobial performance. The eutectogels also possess desirable harsh environmental tolerance properties owing to the strong hydrogen-bonding networks in t-DES. The strain sensors prepared by eutectogels show the highest gauge factor (GF) of 62.8 and a wide detection range (3000%), which can be used to detect human motion even in low-temperature environments. This study will facilitate the progress of supertough and multifunctional eutectogels in wearable electronics.