Skin-friendly PVA/PDA/Tyr-PEAm composite hydrogel with long-term antibacterial and self-recovery ability for wearable strain/pressure sensor

Flexible and self-healing conductive hydrogel, as a typical electronic skin with the function of transmitting sensory signals, has attracted remarkable attentions in the biomaterials field. However, the practical application of electronic skin has been severely limited owing to the potential bacterial infection threats. Here, in order to improve the antibacterial properties of electronic skin, a star-shaped polyetheramide (Tyr-PEAm) derived from L-tyrosine was synthesized and cross-linked into the hydrogel network. A compliant and self-healing conductive hydrogel (defined as PVA/PDA/Tyr-PEAm) was assembled from polyvinyl alcohol (PVA), polydopamine (PDA) and Tyr-PEAm. The hydrogel achieved a comprehensive performance of long-term antibacterial activity (the inhibition zones remained unchanged over 7 days), low hemolysis activity (hemolysis rate of 0.042 %), good conductivity and rapid self-healing ability (healing within 1 s). Therefore, the hydrogel could be used not only as a detection device to check normal skin, but also as the wound skin detection in real time. Furthermore, the good conductivity and rapid self-healing ability contributed to the hydrogel to detect various macro and micro movements of the human body, as well as to recycle as a new sensor. The PVA/PDA/Tyr-PEAm hydrogel that integrated intelligent signals and resisted bacterial infections exhibited broad application prospects in biomedical materials.