Wearable, antibacterial, and self-healable modular sensors for monitoring joints movement ultra-sensitively

Joint disorders seriously affect daily life. Rheumatoid arthritis (RA), a type of chronic autoimmune disorder, causes recession for range of motion (ROM) and joint function loss. Monitoring and recording ROM is regarded as an efficient way for assisting in RA diagnosis at an early stage. Here, a multi-function hydrogel-based sensor was developed to monitor RA motion. With an interpenetrating polymer network (IPN) structure was prepared from self-crosslinked the poly (N-Hydroxyethyl acrylamide –co- Acrylamido-2-methyl-1-propanesulfonic acid) (PHA) network with conductive polymers PEDOT:PSS and Zinc ions, this conductive hydrogel (PHAC) was able to achieve stretchable, sensitive, adhesive and anti-bacterial properties. The hydrogen bonding and ion interaction present in hydrogel network enable PHAC with high stretchable (∼5000 % strain), strong adhesion to connection (61.4 kPa on copper), high conductivity (208.96 mS•cm−1), fast self-healing (recovery to 40 % stretchable properties in10 min) and excellent anti-bacterial behavior. After combining this sensor element with customized printed circuit board (PCB) and detachable battery, the RA monitor system demonstrated the real-time recording, accurate detection of ROM, and long-time stability of signal transmission. This line of research work sheds light on stretchable, sensitive, adhesive, self-healable, anti-bacterial and wireless soft sensors with potential applications in human joint monitoring, personal healthcare diagnosis, and soft robots.