P. Gao, I. MacKay, A. GruberCarreyo, J. Krantz, L. Piccolo, D. Masato
University of Massachusetts-Lowell,
Keywords: micro injection molding, laser ablation, wetting, functional surfaces
Summary:The manufacturing of textured plastic part surfaces can be used to achieve wetting functionalization. The hydrophobicity can allow functionalities such as fluid collection or transport, which are critical for microfluidics. In this research, hierarchical textures were generated on steel mold inserts using femtosecond laser and replicated by micro injection molding technique with polypropylene (PP) and Poly (methyl methacrylate) (PMMA). Results showed that the replication is affected by the geometrical texture design, texture orientation, the rheological and thermal properties of the polymers. The static wetting behavior was investigated on both steel inserts and molded parts and was compared to the theoretical values from Cassie-Baxter and Wenzel models. On the steel inserts and polypropylene samples, the wetting behavior followed Cassie-Baxter model. PMMA samples presented a composite wetting state.