Multifunctional starch-based eutectogels with high mechanical properties, adhesion, self-healing, fatigue resistance and degradability for flexible wearable sensing

Flexible wearable sensors have developed rapidly due to the urgent demands for human motion monitoring. Eutectogel-based soft materials have exhibited great potential for wearable sensing applications. However, it is still a challenge to develop multifunctional eutectogels with excellent mechanical properties, adhesion, self-healing, fatigue resistance and degradability. In this work, a multifunctional starch-based eutectogel was developed by a one-pot and in-situ photo-polymerization method. The eutectogel had excellent stretchability (2710%), high strength (5.43 MPa), toughness (94.38 MJ/m 3 ), Young's modulus (10.23 MPa), adhesion, fatigue resistance (1000 cycles), degradability and a certain degree of self-healing ability. These properties were closely correlated to the synergistic effect among the amylopectin, polyacrylic acid and choline chloride via hydrogen-bond and electrostatic interactions. The mechanical properties of eutectogel can be adjusted by changing the starch content. A wearable sensor based on the eutectogel was realized accurate and stable monitoring of human joint motions. This study addressed the limitations of the dehydration and single function of the traditional hydrogels, and provides a novel way for the development of the multifunctional bio-based gels for next-generation flexible wearable devices.