UIC-2014-024 – High-Rate pumpless fluid transport on open-surface microfluidic devices

Open-surface microfluidics can play a critical role in large spectrum of engineering applications. Unlike embedded-channel microfluidic systems, their open-surface counterparts require no pumps, and can also act against gravity. Open microfluidic systems have been demonstrated using multiple methods. However, most methods require complex fabrication techniques, use external power inputs or produce very slow liquid transport rates. Researchers at UIC have developed a novel substrate patterning method, which can be used to form spatially-selective superhydrophobic/ superhydrophilic surfaces on substrates ranging from glass, paper or plastic to metals. These surfaces can form the base for open-air, pumpless, microfluidic devices that can move fluid efficiently without power input. The invention uses a facile wettability patterning method to produce superhydrophilic domains on a superhydrophobic background. The geometric arrangement of these patterns can be designed to produce complex droplet-handling tasks, some of which occur in 3-D geometries and perform even against gravity. These designs can also be used to control and optimize drop-wise condensation, thus creating significant energy savings in processes involving condensers. The technology works also with lower surface-tension liquids, such as oils and alcohols Mark Krivchenia krivchen@otm.uic.edu (312) 996-6626