Development of Adhesive and Conductive Resilin-Based Hydrogels for Wearable Sensors

Integrating multifunctionality such as stretchability, adhesiveness, and electroconductivity on a single protein hydrogel is highly desirable for various applications, and remains a challenge. Here we present the development of such multifunctional hydrogels based on resilin, a natural rubber-like material with remarkable extensibility and resilience. First, genetically engineered reslin-like proteins (RLPs) with varying molecular weight were biosynthesized to tune mechanical strength and stiffness of the cross-linked RLP hydrogels. Second, glycerol was incorporated into the hydrogels to endow adhesive properties. Next, a graphene–RLP conjugate was synthesized for cross-linking with the unmodified, pristine RLP to form an integrated network. The obtained hybrid hydrogel could be stretched to over four times of its original length, and self-adhered to diverse substrate surfaces due to its high adhesion strength of ∼24 kPa. Furthermore, the hybrid hydrogel showed high sensitivity, with a gauge factor of 3.4...