Bioinspired Capillary Force-Driven Super-Adhesive Filter

Abstract Capturing particles with low, nanonewton scale adhesion is an ongoing challenge for conventional air filters1,2. Inspired by the natural filtration capabilities of mucus-coated nasal hairs3-7, we introduce an efficient biomimetic filter that exploits a thin liquid coating. Here, a stable thin liquid layer is formed on a variety of filter media that generates enhanced particulate adhesion, driven by micro- to sub-micronewton capillary forces8,9. The enhanced particle adhesion results in outstanding filtration of airborne particulates while maintaining air permeability, providing longer filter lifetime and increased energy savings. Moreover, strong adhesion of the captured particles enables effective filtration under high-speed airflow as well as suppression of particle redispersion. We anticipate that these filters with thin liquid layers affords a new way to innovate PM filtering systems.