Improvement in capillary-driven flow by surface modification of polystyrene surfaces

The goal of this work was to improve capillary-driven flow through small channels on a polystyrene plaque. This work was driven by the requirement to move biological fluids on a diagnostic device using only a capillary driving force. Polystyrene surfaces were modified with a hydrophilic coating to increase the surface energy. Changes in the surface energy were quantified by contact angle analysis. Capillary flow through the treated and untreated channels was captured on video using several liquids with known surface tensions. Results from the surface modification work and implications for capillary-driven flow on medical devices will be presented.