Mussel‐Inspired Adhesive and Conductive Hydrogel with Long‐Lasting Moisture and Extreme Temperature Tolerance

TLDR

Conductive hydrogels are promising for bioelectronics that must operate long‑term or under extreme environments, yet traditional hydrogels cannot retain water at cold or hot temperatures. The study develops a mussel‑inspired adhesive conductive hydrogel with long‑lasting moisture retention and extreme temperature tolerance using a water‑glycerol binary solvent. The hydrogel incorporates polydopamine‑decorated carbon nanotubes for conductivity and mechanical reinforcement, while catechol groups and glycerol provide tissue adhesiveness and thermal tolerance from –20 °C to 60 °C. The hydrogel performs as a self‑adhesive bioelectronic platform for biosignal detection in extreme temperatures and as a protective dressing against frostbite or burn injuries.

Abstract

Abstract Conductive hydrogels are a promising class of materials to design bioelectronics for new technological interfaces with human body, which are required to work for a long‐term or under extreme environment. Traditional hydrogels are limited in short‐term usage under room temperature, as it is difficult to retain water under cold or hot environment. Inspired by the antifreezing/antiheating behaviors from nature, and based on mussel chemistry, an adhesive and conductive hydrogel is developed with long‐lasting moisture lock‐in capability and extreme temperature tolerance, which is formed in a binary‐solvent system composed of water and glycerol. Polydopamine (PDA)‐decorated carbon nanotubes (CNTs) are incorporated into the hydrogel, which assign conductivity to the hydrogel and serve as nanoreinforcements to enhance the mechanical properties of the hydrogel. The catechol groups on PDA and viscous glycerol endow the hydrogel with high tissue adhesiveness. Particularly, the hydrogel is thermal tolerant to maintain all the properties under extreme wide tempreature spectrum (−20 or 60 °C) or stored for a long term. In summary, this mussel‐inspired hydrogel is a promising material for self‐adhesive bioelectronics to detect biosignals in cold or hot environments, and also as a dressing to protect skin from injuries related to frostbites or burns.