Abstract: Robust microfluidic mixing devices mix multiple fluid streams passively, without the use of moving parts. In one embodiment, these devices contain microfluidic channels that are formed in various layers of a three-dimensional structure. Mixing may be accomplished with various manipulations of fluid flow paths and/or contacts between fluid streams. In various embodiments, structures such as channel overlaps, slits, converging/diverging regions, turns, and/or apertures may be designed into a mixing device. Mixing devices may be rapidly constructed and prototyped using a stencil construction method in which channels are cut through the entire thickness of a material layer, although other construction methods including surface micromachining techniques may be used.

Abstract: Microfluidic devices having porous membrane valves, which are microfluidic channels or elements having porous materials that restrict fluid flow rate for a given pressure, are provided. Multiple microfluidic valves of this invention can be constructed on a single device so that they have different valving capabilities or impedances, and in unison can control the overall direction of fluid flow. Impedance regions may be constructed in various ways, such as, for example: by inserting porous materials into or between channels; by sandwiching a sheet or layer of porous material between other layers of the device (preferably in stencil form); or by inserting a liquid, solution, slurry, or suspension into microfluidic channels, and then permitting the formation of porous deposits by promoting at least partial evaporation. Adhesive tape may be used for one or more layers of the device.

Abstract: Microfluidic fluid control devices are provided. One microfluidic fluid control device can be used as a uni-directional valve within a microfluidic system. The invention also provides a microfluidic pump mechanism having two unidirectional valves separated by an expandable reservoir. Such devices may be formed in multiple layers and utilize flexible membranes.

Abstract: In accordance with the present invention there is provided a microfluidic heat exchange system for cooling heat-generating components of electronic equipment, computers, lasers, analytical instruments, medical equipment and the like. Both direct contact and indirect contact microfluidic systems are described. Also described are microfluidic systems that incorporate remote heat rejection systems that may be located outside the body of the equipment that contains the heat generating components that need cooling.