Dynamic Non‐Covalent Interactions Incorporated Reprocessable Waterborne Polyurethane with Visible Light Activated Self‐Healing, Antibacterial, Anti‐Fouling, and Strain Sensor Performances

Abstract Multifunctional waterborne polyurethane (WPU) materials with superior mechanical properties, self‐healing capabilities, and reproducibility have attracted significant attention in recent years. In this study, a series of WPU materials incorporating dynamic covalent aromatic Schiff base (ASB) bonds, carbohydrazide (CHZ), and polyhexamethylene guanidine (PHMG) moieties is successfully prepared. The ASB units with visible light‐triggered dynamic exchange functionality are introduced into the soft polyethylene glycol (PEG) segment to realize high chain flexibility and facilitate the exchange of Schiff base bonds, achieving a rapid repair rate during the self‐healing process. By optimizing the soft‐to‐hard segment ratio and the multiple hydrogen bonds adjusted balance between self‐healing capability and mechanical strength, the resulting WPU materials exhibited outstanding mechanical and visible light‐assisted self‐healing performances, which could be maintained in extreme circumstances. Additionally, the remarkable antibacterial, biocompatible, anti‐fouling, self‐cleaning, and reusability properties endow these WPU materials to be an excellent candidate to be directly applied to contact with human skin. After ionic liquids (ILs) doping, the ionic skin with superior mechanical property, conductivity, sensitivity, and stability can be obtained and utilized as a strain sensor to monitor the movement of human joints. This proof‐of‐concept study not only promotes the performance of WPU materials but also provides a promising candidate for next‐generation intelligent coatings and ionic skin, offering a versatile platform for multifunctional material design and sustainable applications.