Sample capture transport of biological fluids, like blood flow in diabetes glucose monitors, often requires microfluidic actuation. Current commercial methods used in diabetes glucose monitors usually involve porous materials or hydrogels, but these strategies are limited in fluid control. Surface wettability gradient actuation is an approach widely used in various other microfluidic or lab-on-a-chip systems. Here we design and fabricate a droplet-actuation device that relies purely on capillary pressure gradients induced by surface topologies. We discuss the theoretical capabilities of directing such fluid flows using no thermal gradients or external power sources. Current work focuses on pillar capillary designs on a polydimethylsiloxane (PDMS) substrate and water droplets (0.25 ~ 5 Î¼L) in low Bond number. The work is extending to more complex biological fluids including blood.
Project end date: 01/30/13