Lacrimal Gland‐Inspired Active Replenishing Slippery Surface for Robust Anti‐Pollution Optical Windows

As a crucial part of optical systems, optical windows play an important role in medicine and industry, yet their performance is often compromised by surface contamination. Inspired by the lacrimal gland's tear storage and secretion mechanism, we propose a Lacrimal Gland‐inspired Active Replenishing Slippery Surface (ARSS) fabricated by femtosecond laser microprocessing. The surface integrates embedded storage cabins and a thermally responsive heating circuit such that localized heating creates a temperature gradient upon activation, inducing both thermal expansion of the stored silicone oil and Marangoni flow for stimulus‐responsive lubricant secretion to replenish the sliding layer. The fabricated surface exhibits high transparency exceeding 90%, excellent self‐cleaning properties against challenging pollutants including marine organisms, dust, and salt crystallization, and exceptional durability withstanding over 50 000 droplet sliding tests without performance degradation. This bioinspired design offers a long‐lasting anti‐fouling solution for optical windows, with significant potential for applications in marine engineering, biomedical devices, and other demanding environments.