Abstract: A sheath flow system having a channel with at least one fluid transporting structure located in the top and bottom surfaces situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. The design can be readily incorporated into microfluidic chips without the need for special manufacturing protocols. Uses include extruding materials and/or fabricating structures.

Abstract: A sheath flow system having a channel with first and second fluid transporting structures located on opposing surfaces facing one another across the channel in the top and bottom surfaces of the channel situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. The design can be readily incorporated into microfluidic chips without the need for special manufacturing protocols.

Abstract: A magnetic bead trap-and-mixer includes a channel having openings at opposing ends, and a rotor adjacent to the channel and comprising a permanent magnet, wherein the rotor is adapted to apply a magnetic field to the channel of sufficient strength to direct the movement of magnetic beads therein. In aspects, the channel is straight and/or has narrowed end. In further aspects, the rotor generates in the channel areas of areas of strong magnetic fields alternating with areas of very weak magnetic fields and the strong magnetic fields extend entirely across the channel.

Abstract: A sheath flow system having a channel with at least one fluid transporting structure located in the top and bottom surfaces situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. The design can be readily incorporated into microfluidic chips without the need for special manufacturing protocols. Uses include extruding materials and/or fabricating structures.

Abstract: A sheath flow system having a channel with at least one fluid transporting structure located in the top and bottom surfaces situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. The design can be readily incorporated into microfluidic chips without the need for special manufacturing protocols. Uses include extruding materials and/or fabricating structures.

Abstract: A device having: a laminar flow channel for liquids; two or more electrodes; a confining fluid inlet; a sample inlet; and a meter for measuring the impedance of any fluid between the electrodes. The device may have one or more specific binding sites, or it may have sheathing and unsheathing fluid transporting structures. A method of: providing the device; flowing a confining fluid and a conductive liquid that may contain cells or particles through the channel as described herein; and measuring the impedance between the electrodes.

Abstract: A sheath flow system having a channel with at least one fluid transporting structure located in the top and bottom surfaces situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. The design can be readily incorporated into microfluidic chips without the need for special manufacturing protocols.

Abstract: Flow step focusing isolates and concentrates a molecule of interest by flowing a liquid comprising a molecule of interest through a main channel having an inlet and an outlet with application of a first pressure at the inlet; applying a voltage along the channel during the flowing, wherein the voltage is configured to have a polarity such that it drives the molecule of interest in a direction opposite the flow of the liquid; controlling the first pressure and/or the voltage in a manner so as to trap and concentrate the molecule of interest in a region of the main channel; and removing the concentrated molecule of interest from the channel by recovering a portion of the liquid from a side channel diverging from the main channel, wherein the side channel is maintained at a pressure lower than the first pressure. Also disclosed is an apparatus for such.

Abstract: Flow step focusing isolates and concentrates a molecule of interest by flowing a liquid comprising a molecule of interest through a main channel having an inlet and an outlet with application of a first pressure at the inlet; applying a voltage along the channel during the flowing, wherein the voltage is configured to have a polarity such that it drives the molecule of interest in a direction opposite the flow of the liquid; controlling the first pressure and/or the voltage in a manner so as to trap and concentrate the molecule of interest in a region of the main channel; and removing the concentrated molecule of interest from the channel by recovering a portion of the liquid from a side channel diverging from the main channel, wherein the side channel is maintained at a pressure lower than the first pressure. Also disclosed is an apparatus for such.

Abstract: A fiber includes one or more layers of polymer surrounding a central lumen, and living animal cells disposed within the lumen and/or within at least one of the one or more layers, wherein the fiber has an outer diameter of between 5 and 8000 microns and wherein each individual layer of polymer has a thickness of between 0.1 and 250 microns. Also disclosed are model tissues including such fibers, and method of making such fibers. The fibers can serve as synthetic blood vessels, ducts, or nerves.

Abstract: A sheath flow system having a channel with first and second fluid transporting structures located on opposing surfaces facing one another across the channel in the top and bottom surfaces of the channel situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity.

Abstract: A computational “toolbox” can be used for the a priori design of optimized fluidic components. These components include a channel under low-Reynolds number, pressure-driven flow, with an arrangement of grooves cut into the top and/or bottom to generate a tailored cross-channel flow. An advection map for each feature (i.e., groove of a particular shape and orientation) predicts the lateral transport of fluid within the channel due to that feature. Applying the advection maps in sequence generates a representation of the outflow distribution for complex designs that combine one or more features. Therefore, the effect of the complex three-dimensional flow field can be predicted without solving the governing flow equations through the composite geometry, and the resulting distribution of fluids in the channel is used to evaluate how well a component performs a specified task. The toolbox is applied to determine optimal combinations of features for specified mixer sizes and mixing metrics.

Abstract: Flow step focusing isolates and concentrates a molecule of interest by flowing a liquid comprising a molecule of interest through a main channel having an inlet and an outlet with application of a first pressure at the inlet; applying a voltage along the channel during the flowing, wherein the voltage is configured to have a polarity such that it drives the molecule of interest in a direction opposite the flow of the liquid; controlling the first pressure and/or the voltage in a manner so as to trap and concentrate the molecule of interest in a region of the main channel; and removing the concentrated molecule of interest from the channel by recovering a portion of the liquid from a side channel diverging from the main channel, wherein the side channel is maintained at a pressure lower than the first pressure. Also disclosed is an apparatus for such.

Abstract: A sheath flow system having a channel with at least one fluid transporting structure located in the top and bottom surfaces situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. A wide variety of shapes of fibers and other materials can be produced from this system through the use of polymerizable material.

Abstract: A sheath flow system having a channel with at least one fluid transporting structure located in the top and bottom surfaces situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. The design can be readily incorporated into microfluidic chips without the need for special manufacturing protocols.

Abstract: A sheath flow system having a channel with at least one fluid transporting structure located in the top and bottom surfaces situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. The design can be readily incorporated into microfluidic chips without the need for special manufacturing protocols.

Abstract: A micro-fluidic device and a method of use are disclosed. The device includes a micro-channel with an inlet port at a first end and an outlet port at a second end. A first fluid, such as air or liquid or both, is disposed in the micro-channel. A focusing structure extends into the micro-channel, whereby when a pulse of a second fluid is introduced to the channel, the pulse advances adjacent sides of the micro-channel at a faster rate than would occur without the focusing structure.

Abstract: A sheath flow system having a channel with at least one fluid transporting structure located in the top and bottom surfaces situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. A wide variety of shapes of fibers and other materials can be produced from this system through the use of polymerizable material.

Abstract: A magnetic bead trap-and-mixer includes a channel having openings at opposing ends, and a rotor adjacent to the channel and comprising a permanent magnet, wherein the rotor is adapted to apply a magnetic field to the channel of sufficient strength to direct the movement of magnetic beads therein. In aspects, the channel is straight and/or has narrowed end. In further aspects, the rotor generates in the channel areas of areas of strong magnetic fields alternating with areas of very weak magnetic fields and the strong magnetic fields extend entirely across the channel.

Abstract: A sheath flow system having a channel with at least one fluid transporting structure located in the top and bottom surfaces situated so as to transport the sheath fluid laterally across the channel to provide sheath fluid fully surrounding the core solution. At the point of introduction into the channel, the sheath fluid and core solutions flow side by side within the channel or the core solution may be bounded on either side by the sheath fluid. The system is functional over a broad channel size range and with liquids of high or low viscosity. The design can be readily incorporated into microfluidic chips without the need for special manufacturing protocols.