Leaf-Inspired Pre-Filtration Inlet Tubes for Reliable Ammonia Monitoring Under Dust-Laden Conditions

Reliable ammonia (NH3) monitoring is essential for environmental control in intensive livestock production, where airborne particulate matter (PM) can interfere with gas sampling and shorten filter service life. In this study, leaf-inspired pre-filtration inlet tubes were developed by integrating the strip-spiny morphology of juniper leaves and leaf-surface grooves, ridges, and trichomes into 12 configurations. Their filtration efficiency, pressure drop, quality factor, reusability, and particle-transport mechanisms were evaluated experimentally and through computational fluid dynamics simulations. N-S-G, N-S-T, and N-B-G achieved total PM filtration efficiencies of 81.6%, 79.1%, and 78.4%, respectively. The optimized N-S-G increased total filtration efficiency by nearly 40% compared with the non-bionic inlet tube and exhibited the highest overall quality factor. Simulations indicated that particle capture was enhanced by successive inertial impaction and interception on bionic surfaces and tube walls, while the meandering flow path promoted additional deposition with limited pressure loss. N-S-G also extended membrane-filter service life by 99.27% and reduced NH3 measurement deviation from 7.42 to 0.97 ppm. These results demonstrate that leaf-inspired pre-filtration can improve the durability and reliability of NH3 monitoring in dust-laden livestock environments.