Authors: R.M. Moroney, R. Amantea and S.E. McBride
Affilation: Sarnoff Corporation, United States
Pages: 526 - 529
Keywords: arrays, microfluidics, surface tension, systems, valves
We have developed a passive valve element for use in a high-density chemical synthesis machine. The element stops fluid flow by the surface tension forces occurring at small channel openings. The openings are circular holes about 100 µm in diameter, referred to as capillary breaks. They have been built and tested in both glass and silicon, the holding pressure of the capillary break is on the order of 1500 Pa, or 5.9" of water column. Before yielding, the capillary break acts as an equivalent capacitance in the fluidic circuit. Details of the capacitance model are presented, along with supporting experimental work and computational fluid dynamics (CFD) simulations. This modeling lays the foundation for understanding the valveís operation in large arrays.