Bioinspired Wavy Self‐Secretion Surface for Anti‐Encrustation

Abstract Indwelling catheters are highly needed in medical diagnostics, treatment, and implantations. However, the obstruction arisen from biofilm formation and crystalline encrustation hinders the long‐term indwelling use of catheters. Here, inspired by kelp, a wavy self‐secretion surface (WSS) with robust anti‐encrustation is established by integrating wavy surface of polydimethylsiloxane and self‐secretion of silicone oil. WSS possesses remarkable resistance to biofluids, bacteria, and urinary crystals, achieving an anti‐encrustation efficiency of 96.44% of urine crystals, and showing superior self‐cleaning capability compared to the non‐engineered counterpart. The oil film on WSS significantly reduces direct contact between the urinary contents and the WSS surface, while the wavy structure induces flow turbulence, further enhancing the anti‐adhesion properties. Moreover, the high stability of the oil film, offered by the wavy structure and the polymeric brush, and the sustained self‐secretion ensure the long‐term use of WSS. Therefore, the work here establishes a bioinspired strategy for the surface design of indwelling catheters that can find wide applications in long‐term indwelling medical devices.