Antibacterial, Stretchable, and Self-Adhesive Laponite-TA Based Conductive Hydrogel Sensor for Human Motion Detection

Abstract

Due to their biocompatibility and tissue-like properties, hydrogels have garnered considerable interest in bioelectronics field. Nevertheless, their practical implementation is limited by factors such as inadequate mechanical strength, weak interface adhesion, and the lack of antimicrobial properties. To address these challenges, a novel conductive hydrogel was synthesized through free radical polymerization, incorporating laponite (LA), tannic acid (TA), polyacrylic acid (PAA), and polyacrylamide (pAAm). An innovative approach was employed to enhance LA's dispersion through ionic liquid (IL) in water through electrostatic interactions. The integration of TA, PAA, and PAAm with LA sheets via multiple hydrogen bonds resulted in excellent mechanical properties. The resulting P(AAm-AA)/IL-LA/TA hydrogel exhibits impressive characteristics, including a fracture stress of 0.44 MPa, a strain of 1800%. Notably, the hydrogel's TA component exhibits strong antibacterial activity against Staphylococcus aureus and Escherichia coli. This advanced hydrogel sensor effectively monitors human movements, displaying a gauge factor of 12.7. Furthermore, its versatile and conductive nature facilitates adhesion to a wide range of substrates, making it a promising candidate for applications in human activity monitoring, electronic devices, and medical health surveillance.