DLP-printed bio-based mini-channel filters for water filtration: influence of channel size and surface quality on mechanical and filtration performance

This study demonstrates DLP-printed mini-channel filters. Arrays with 0.5 and 1.0 mm apertures were made from plant-derived UV resin and characterized by geometry, wettability, FT-IR, SEM-EDS, three-point bending with FEA, and filtration tests. Cured resin showed contact angles of 72° (flat), 86° (0.5 mm), and 78° (1.0 mm). Time-lapse imaging showed imbibition in 1.0 mm channels (~0.26 s) but slower uptake in 0.5 mm channels (~95 s), consistent with capillary and Washburn scaling. Flexural tests showed higher strength for 0.5 mm channels (12.41 MPa) but greater flexibility for 1.0 mm channels (10.33 MPa); failure modes matched FEA, which reproduced maximum stresses within 0.16% (0.5 mm) and 8.32% (1.0 mm). Filtration showed sawdust retention yet more clogging for 0.5 mm, higher throughput but lower capture for 1.0 mm, with performance converging at 5% sawdust. SEM revealed clogging-prone micro-bumps, while FT-IR confirmed polymerization and sawdust-related bands, showing resins enable efficient, reliable filtration.