Highly stretchable, self-healable, and self-adhesive ionogels with efficient antibacterial performances for a highly sensitive wearable strain sensor.

Gel-based strain sensors with multi-functional outstanding properties have gained considerable attention. However, conventional gel sensors suffer from unsatisfactory mechanical properties and adhesion, and also a lack of self-healing and antibacterial ability. Herein, a multi-functional ionogel has been constructed based on Ag-Lignin nanoparticles (Ag-Lignin NPs), polyurethane (PU), and ionic liquids. The obtained ionogel exhibited excellent mechanical properties (tensile strength: 3.14 MPa, elongation at break: 1241%), and was conferred self-healing ability by introducing the disulfide bonds into the main chain (the best self-healing efficiency is 97.6%). The dynamic catechol redox system based on Ag-Lignin NPs endows the ionogel with repeatable and long-lasting adhesiveness. Besides, the obtained ionogel also presented favorable antibacterial and UV absorption properties. The sensor based on the ionogel possesses good and stable sensing performance. This study proposes a bright new strategy to fabricate multi-functional ionogel-based sensors exerting broad application prospects in the field of human movement and personalized physiological health monitoring.