Stretchable, conductive PAni-PAAm-GOCS hydrogels with excellent mechanical strength, strain sensitivity and skin affinity

Abstract Stretchable, conductive and skin-friendly materials are highly desired due to their enormous potential in flexible wearable electronic devices, biosensors and so forth. Herein, a novel type of hydrogels was prepared via two-step in-situ radical polymerization of acrylamide (AAm) and aniline (Ani) monomers in the matrix of graphene oxide (GO) and chitosan (CS) via LiOH/urea solvent. The synergetic integration of nanocomposite (NC) and multi-network (multi-N) endowed PAni-PAAm-GOCS electrically conductive hydrogels (ECHs) with excellent mechanical properties. The morphology and structure of PAni nanofiber networks were subtly regulated by changing the proportion of phytic acid/HCl, resulting in the increase of conductivity of PAni-PAAm-GOCS ECHs. The tensile strength, elongation and conductivity of ECH66 could reach 0.80 MPa, 360% and 2.88 S/m, respectively. Furthermore, the excellent skin affinity was characterized by allergy patch tests on the skin of rats and human body. The strategy to design tough, stretchable and conductive hydrogels by NC and multi-N provided such hydrogels great possibility of practical application for flexible wearable electronic devices.