Recyclable self-secreting autonomous healing dielectrics for millisecond water quality sensing

Developing a sustainable, in-situ responsive sensing method for continuously monitoring water quality is crucial for water use and quality management globally. Conventional water quality monitoring sensors face challenges in achieving ultrafast response time and are non-recyclable. We present a self-assembly approach for a closed-loop recyclable, autonomous self-healing and transparent dielectric material with nanostructured amphiphobic surfaces (termed 'ReSURF'). Our approach uses tribo-negative small molecules that spontaneously secrete onto the surface of the fluorine dielectric matrix via biomimetic microphase separation within minutes. ReSURF devices achieve millisecond water quality sensing response time (~6 ms), high signal-to-noise ratio (~30.7 dB) and can withstand large mechanical deformations (>760%, maximum of 1000% strain). We show ReSURF can be readily closed-loop recycled for reuse, underscoring its versatility. We further demonstrated its use in a soft stretchable fish-like robot for real-time water contamination (including perfluorooctanoic acid, a member of per- and polyfluoroalkyl substances (PFAS) and oily pollutants) assessments.