An Amylopectin-Enabled Skin-Mounted Hydrogel Wearable Sensor

Self-adhesiveness is highly desirable for conformal and seamless wearable electronics. Here, a starch-tackifying method is proposed to obtain adhesive and robust hydrogel conductors with the assistance of amylopectin (Amy). The conductive hydrogels are composed of Amy/poly(acrylamide-acrylic acid) polymer networks, which can be assembled into wearable sensors. The hydrogels rely on physical interactions such as hydrogen bonding that can be generated on the surface of the material, including skin, to exhibit robust and repeatable self-adhesive behaviors. Besides, the construction of a covalent and dynamic dual cross-linking network endows the hydrogel with good mechanical properties to bear repeated stretching and flexible deformation. In particular, the hydrogel is assembled into a wearable stretchable and compressible sensor and exhibits a repeatable and stable resistance signal variation for detecting both large and tiny scale human activities and physiological signals, such as bending of joints, speaking, walking, and jumping. Accordingly, the amylopectin-enabled skin-mounted hydrogel sensor can be considered as an ideal choice for human movement monitoring and personal health diagnosis.