Paper-like Surface Microstructure Fabricated on a Polymer Surface by Femtosecond Laser Machining.

Abstract

In this study, we demonstrate the precise control of fluid flow using femtosecond (FS) laser-induced microstructures. A microgroove structure inscribed on a poly(methyl methacrylate) (PMMA) substrate functions as a superhydrophilic membrane similar to paper. We first estimated the flow rate for pure water on microgrooves fabricated at various laser fluences in the range from 9.2 to 100.8 J/cm2. The results showed that the flow rate could be tuned in the range from 0.30 to 12.07 μL/s by varying the laser irradiation parameters. The fluid flow was reproducible, with a calculated relative standard deviation (RSD%) of less than 8% in the flow rate. We then fabricated a microfilter for blood separation and estimated its filtration ability using artificial blood containing resin microparticles. This method would be useful in a technology related to a paper-based diagnostic device for precise reagent manipulation.