Abstract: A method of controlling fluid flow within a microfluidic circuit using external valves and pumps connected to the circuit is disclosed. The external valves and pumps, which are not a part of the microfluidic substrate, control fluid pumping pressure and the displacement of air out of the fluid circuit as fluid enters into the circuit. If a valve is closed, air cannot be displaced out of circuit, which creates a pneumatic barrier that prevents fluid from advancing within the circuit (under normal operating pressures). Applications of this method of fluid control are explained.

Abstract: A splitter for multi-layer microfluidic devices is provided. The splitter includes multiple forked channels defined in two or more device layers. The forked channels communicate fluidically at overlap regions. The overlap regions, in combination with symmetrical channel geometries balance the fluidic impedance in the system and promote even splitting.

Abstract: The invention concerns a multichannel element, comprising at least a first ring of channels intermingled with a second ring of channels. The invention also concerns a method for making such an element, and a module comprising same. The invention is applicable to tangential filtering.

Abstract: A capillary reactor distribution device comprising first and second capillary pathways (2, 3) which meet at a junction (5) and a third capillary pathway (4) which leads away from the junction (5), the capillary pathways (2, 3, 4) being dimensioned such that, when first and second immiscible fluids (14, 15) are fed along respectively the first and second capillary pathways (2, 3) under predetermined laminar flow conditions, the first and second fluids (14, 15) chop each other into discrete slugs (16, 17) which pass along the third capillary pathway (4). Molecular mixing between the fluids (14, 15) takes place by way of axial diffusion between adjacent slugs (16, 17) and by way of internal circulation within each slug (16, 17) as the slugs (16, 17) progress along the third capillary pathway (4).

Abstract: Methods of controlling fluid flow through microchannels by use of passive valves or stopping means in the microchannels is presented. The passive valves act as pressure barriers impeding flow of solution past the stopping means until enough force is built up to overcome the force of the pressure barrier. Well planned use of such stopping means acting as passive valves allows the flow of fluids through microchannels to be regulated so as to allow fluids to be mixed or diluted after being introduced via a single channel, or to be split into multiple channels without the need for individual pipetting. Flow through the multiple channels can be regulated to allow a series of sister wells or chambers to all fill prior to the fluid flowing beyond any one of the sister wells or chambers. The filling of sister wells or chambers in this manner allows all wells or chambers to undergo reactions in unison. The use of air ducts to prevent trapping of air in the microchannels is also presented.

Abstract: A microchip device has at least one passage along which a liquid can be moved by applying a voltage to the liquid. The device includes a passage member (10, 12) in which the passage is formed and which has an aperture (20, 22). Additionally the device includes an electrode member (14) that comprises an electrode (42, 44) and that is separably engageable with the passage member. The device includes a reservoir in fluid communication with the passages for holding a liquid. The electrode member cooperates with the aperture so that the electrode is in fluid communication with the passage without the electrode member obstructing the opening of the reservoir.

Abstract: The present invention relates to microfluidic devices and to their method of manufacture. The microfluidic devices are original by their specific structure (of sandwich type) and by the materials from which they are made (mainly glasses, glass ceramics, ceramics), and also by their specific method of manufacture, which is based on a vacuum-forming operation. The microfluidic device includes a first assembly including a microstructure and a first substrate, wherein the microstructure is constructed and arranged on the substrate under vacuum. A second assembly includes a second substrate positioned on the microstructure after the first assembly is presintered and adhered thereto by heat treatment to form a one-piece microstructure defining at least one recess between the first and second substrates.

Abstract: The present invention is an improved vessel body for use in uniform plug-flow fluid applications, such as chromatography and adsorption bed processes. The improved vessel is toroidal shaped and allows for a simpler distribution and collection system, which is likewise claimed.

Abstract: Methods and apparatus for controlling fluid flow through microchannels by use of passive valves or stopping means comprised of abrupt microchannel widenings in the microchannels are presented. Such passive fluid flow barriers create pressure barriers impeding flow of solution past the passive fluid flow barriers until enough force is built up to overcome the force of the pressure barrier. Use of such stopping means acting as passive barriers or valves allows the flow of fluids through microchannels to be regulated so as to allow fluids to be mixed or diluted after being introduced via a single channel, or to be split into multiple channels without the need for individual pipetting. Flow through the multiple channels can be regulated to allow a series of sister wells or chambers to all fill prior to the fluid flowing beyond any one of the sister wells or chambers. The filling of sister wells or chambers in this manner allows all wells or chambers to undergo reactions in unison.

Abstract: A manifold for distributing a fluid. The manifold can be used to distribute a fluid to and from a microvalve. The manifold includes a first plate having a groove formed in one face thereof. A second plate is fixed to the first plate so as to cover the groove to form a fluid passage through the groove. First and second bores are formed through at least one of the first plate and the second plate to form an inlet and an outlet, respectively, of the fluid passage. According to a method of manufacturing, etching the first plate forms the groove. Preferably, an etching process also forms the first and second bores. Also, preferably, the first plate is one of a plurality of plates formed from a single sheet of material. Preferably the sheet of material is a standard sized sheet with locating indicia enabling assembly of the manifold with standard pick and place equipment.

Abstract: A static fluid and a second fluid are placed into contact along a microfluidic free interface and allowed to mix by diffusion without convective flow across the interface. In accordance with one embodiment of the present invention, the fluids are static and initially positioned on either side of a closed valve structure in a microfluidic channel having a width that is tightly constrained in at least one dimension. The valve is then opened, and no-slip layers at the sides of the microfluidic channel suppress convective mixing between the two fluids along the resulting interface. Applications for microfluidic free interfaces in accordance with embodiments of the present invention include, but are not limited to, protein crystallization studies, protein solubility studies, determination of properties of fluidics systems, and a variety of biological assays such as diffusive immunoassays, substrate turnover assays, and competitive binding assays.

Abstract: The invention provides microfluidic devices with embedded fluidic impedances. Such impedances do not allow fluid to pass at a low differential pressure, but allow fluid to flow at a higher differential pressure. Impedances are formed by the three dimensional overlap of two or more channels contained within layers of the device. Such devices can be rapidly protyped and can be assembled to contain multiple fluidic impedances to perform complex fluid handling tasks, including metering defined volumes of samples and dividing samples into aliquots.

Abstract: The present invention relates to microfluidic devices and to their method of manufacture. The microfluidic devices are original by their specific structure (of sandwich type) and by the materials from which they are made (mainly glasses, glass ceramics, ceramics), and also by their specific method of manufacture, which is based on a vacuum-forming operation. The microfluidic device includes a first assembly including a microstructure and a first substrate, wherein the microstructure is constructed and arranged on the substrate under vacuum. A second assembly includes a second substrate positioned on the microstructure after the first assembly is presintered and adhered thereto by heat treatment to form a one-piece microstructure defining at least one recess between the first and second substrates.

Abstract: The invention discloses a method for fine control of the flow rate of a liquid by a microvalve device without using any mechanical structures. The method comprises, while passing the liquid through a flow channel penetrating a substrate of a heat-insulating material, the temperature of the liquid in the flow channel is decreased below the freezing point of the liquid by a temperature-controlling means such as a Peltier element facing the flow channel to close the flow channel by the solidified liquid and the temperature of the solidified liquid is increased above the melting point thereof to cause thawing of the solid resulting in re-opening of the flow channel.

Abstract: Microfluidic coupling devices capable of connecting more than one microfluidic module together to form a larger, integrated system are described. These devices are constructed in a number of ways. In a certain embodiments, the coupler is constructed from laminated materials and mates to one or more microfluidic devices using adhesive. The device can be used to place fluid into a microfluidic device, to remove fluid from a microfluidic device, or to transfer fluid between two or more microfluidic devices. Also described are modular microfluidic systems formed from microfluidic modules made using various techniques and/or useful for performing various functions.

Abstract: Fluid and fuel delivery systems reducing pressure fluctuations and engines including such systems are disclosed. Such systems use a conduit that attenuates pressure fluctuations. Preferably, the conduit attenuates pressure fluctuations by reflecting a portion of a pressure wave within the fluid flow so that reflected pressure waves within the flow interfere with incident pressure waves within the flow, thereby reducing the pressure fluctuations in one embodiment, such a conduit may be formed as a quarter wave stub, in line with the fluid flow. Advantageously, exemplary of the invention, hoot noise in an engine may be reduced by damping pressure fluctuations in the fuel delivery system to the engine.

Abstract: A method for reducing frictional loss in unlined tunnels or other tunnels with a rough wall surface and/or irregular cross section. A flexible or rigid pipe with a cross section similar to or somewhat less than the largest circular open cross section of the tunnel is introduced into the tunnel and attached continuously or at certain points to parts of the tunnel wall. Apparatus for ensuring that a superpressure occurs within the pipe relative to its outside during flow are also introduced.

Abstract: A simple microfluidic actuator includes a sealed vacuum chamber actuated by providing a current to a thin film heater, which in turn weakens and, under the atmospheric pressure differential, breaks a diaphragm sealing said vacuum chamber whereby the vacuum inside said chamber is released. By applying the microfluidic actuator to a microfluidic network the resulting pressure differential can be used to generate a pumping force with the microfluidic network. The chamber may be prepared in a silicon, glass, or plastic substrate. The diaphragm may be a metallic gas-impermeable film. A releasing member comprising a thin-film metallic heater is then microfabricated on the diaphragm. The assembly so prepared may be bonded to a glass or plastic substrate that contains a network of microchannels. The microfluidic actuator is suited for a microfluidic platform in generating driving powers for operations including pumping, metering, mixing and valving of liquid samples.

Abstract: A micro-electromechanical system and method for continuous laminar fluid mixing. An embodiment of the invention described in the specification includes a mixing channel, a first delivery channel that is connected to the mixing channel, and a second delivery channel that is connected to the mixing channel. A first pump mechanism produces pulses in the first delivery channel. A second pump mechanism produces pulses in the second delivery channel. The first pulsed fluid stream and the second pulsed fluid stream merge in the mixing channel to form a mixed fluid. The pulses in the fluids operate to distort the interface between the fluids to facilitate diffusion between the fluids.

Abstract: The present invention relates to a device for controlling a liquid flow in a liquid channel, comprising: an elongate liquid holder in which a liquid channel is provided in longitudinal direction; first voltage means for applying a first voltage difference over substantially the longitudinal direction of the liquid channel; a conductor member arranged in at least a part of the liquid channel against the liquid holder; an insulator member arranged in the liquid channel against at least the conductor member; second voltage means for providing a second voltage difference between the conductor member and the liquid in the liquid channel; wherein the thickness of the insulator member is a maximum of 1 &mgr;m and preferably in the order of magnitude of some tens of nanometres.

Abstract: A device (10) for treating a continuously moving liquid has a liquid inlet (12) and a liquid outlet (14) at opposite ends of a generally annular passage (16). The passage has a restriction (18) which is generally cylindrical and which, at its outlet (22) is formed with an annular shoulder (24) which provides an abrupt change in the diameter of the passage. An obstruction (26) in the form of a wire extends across the restriction (18) adjacent the outlet (22). The restriction (18) serves to increase the speed of liquid flowing through the passage, thus reducing the liquid pressure. The obstruction (26) also assists in reducing the liquid pressure. The device reduces the liquid pressure below a level at which cavitation occurs in order to induce cavitation.

Abstract: Microfluidic devices having porous materials that restrict fluid flow rate for a given pressure are provided. Multiple porous regions can be constructed in a single device so that they have different valving capabilities or impedances, and in unison can control the overall direction of fluid flow. Porous regions can be constructed in various ways, such as, for example: by inserting porous materials into or between channels; by sandwiching one or more sheets or layers of porous materials between other layers of a device; or by inserting a liquid, solution, slurry, or suspension into a microfluidic channel 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 such a microfluidic device.

Abstract: Microfluidic devices for splitting an established fluidic flow through a microfluidic channel among multiple downstream microfluidic channels include a plurality of elevated flow resistance regions to promote precise and predictable splitting. Each elevated resistance region imparts a flow resistance that is substantially greater than the characteristic resistance to established flow of its associated downstream channel. Elevated flow resistance regions may include one or more porous materials and/or alterations to the channel geometry of at least a portion of a downstream channel.

Abstract: The invention relates to a miniaturized fluid flow switch which enables a directed deflection or deviation of a fluidic test current injected into a fluidic carrier current. The aim of the invention it to provide a fluid flow switch which does not require any moveable parts and with which no restricting preconditions exist with regard to the fluid media to be used. To this end, the inventive switch is comprised of at least two carrier current channels (11, 12) and of a test current channel (2) which, together, open into a distribution chamber (3) to which at least two discharge channels (41, 42) connect. The carrier current channels (11, 12) are connected to a common inlet (10), and at least the carrier current channels (11, 12) are respectively placed, in particle sections, in close thermal contact with controllable heating devices (5).

Abstract: A fluidic nozzle having multiple operating modes comprising a fluidic oscillator circuit having an oscillation chamber having an upstream end and a downstream end and a power nozzle at the upstream end for introducing a jet of a liquid (water) into the oscillation chamber. An outlet throat at the downstream end has a width, which does not allow the oscillation circuit to fill up and start to oscillate without entrained liquid. A pair of control ports are at the upstream end of the oscillation chamber and a pair of feedback passages connect said control ports to downstream ends of said oscillation chamber adjacent said outlet throat. A pair of controllable entrainment holes are provided in the oscillation chamber at the upstream end and a valve opens and closes the entrainment holes, such that when the entrainment holes are open to air, air is entrained and the oscillator does not oscillate.

Abstract: The present invention provides multi-layer microfluidic systems, by providing additional substrate layers, e.g., third, fourth, fifth and more substrate layers, mated with the typically described first and second layers. Microfabricated elements, e.g., grooves, wells and the like, are manufactured into the surfaces between the various substrate layers. These microfabricated elements define the various microfluidic aspects or structures of the overall device, e.g., channels, chambers and the like. In preferred aspects, a separate microscale channel network is provided between each of the substrate layers.

Abstract: Control of fluid motion within microcavities is carried out using microstructures in the cavities having cantilever elements that are coupled to a substrate to receive vibrations therefrom. The cantilever elements can be excited into resonance at one or more resonant frequencies. By selection of the shape of the cantilever elements, their position in the microcavity, the spacing of the cantilever elements from the walls of the cavity, and the frequency at which the cantilever elements are excited, the direction of pumping of fluid through the cavity can be controlled, blocked or diverted.

Abstract: Microfluidic devices and methods for metering discrete plugs of fluid are provided. The microfluidic devices include a trunk channel and a branch channel having an impedance region. A fluid is supplied to the trunk channel and fills the branch channel to the impedance region. The fluid is then flushed from the trunk channel leaving the branch channel filled. Because the branch channel has a volume, a discrete plug of the fluid having a volume substantially equal to that of the branch channel is formed.

Abstract: Microfluidic devices for splitting an established fluidic flow through a microfluidic channel among multiple downstream microfluidic channels include a plurality of elevated flow resistance regions to promote precise and predictable splitting. Each elevated resistance region imparts a flow resistance that is substantially greater than the characteristic resistance to established flow of its associated downstream channel. Elevated flow resistance regions may include one or more porous materials and/or alterations to the channel geometry of at least a portion of a downstream channel.

Abstract: A molded fluid device having a power nozzle with a width W and a coupling passage coupling a source of fluid to the power nozzle. The coupling passage is formed on one chip or insert surface and has a planar enlargement and a plurality of posts spaced across the enlargement, the spacing S between each post being less than the width of the power nozzle with the sum of spacing S being greater than the width W. A liquid spray nozzle is formed on an opposing chip surface and connected to the coupling passage downstream of the posts.

Abstract: A device for moving a fluid in a fluidics system. The device may include one or more controllably openable closed chambers. The pressure within the closed chamber(s) is lower than the ambient pressure outside the fluidics system or lower than the pressure within another channel of the fluidic system. The closed chamber(s) is configured for being controllably opened. The chamber (or chambers) is configured such that when a chamber is opened the chamber is in fluidic communication with a flow channel included within the fluidics system. The fluid may be moved into the flow channel or may be moved within the flow channel. The fluid may be a liquid, a gas, a mixture of gases or an aerosol. The fluidics system may include a controller for controlling the opening of a selected chamber or chambers.

Abstract: A modular microfluidic system includes a plurality of discrete microfluidic modules each capable of performing at least one operation and at least one microfluidic coupling device for fluidically coupling the modules to perform a sequence of operations. The microfluidic modules and coupling devices may be constructed according to various techniques. In one embodiment, coupling devices are fabricated from multiple layers and each include a fluidic inlet port, a fluidic outlet port, and at least one sandwiched stencil layer having a microfluidic channel formed therein. Also described are integrated microfluidic systems and methods capable of performing various sequences of operations.

Abstract: A method and apparatus for ejecting a second fluid into the near-wall region of the boundary layer of a first fluid, so that the second fluid hugs the wall. This alone reduces drag by modifying the behavior of the near-wall structure, thereby reducing the frequency of burst and sweep cycles, even when the first and second fluids are identical. Further, one or more additives, such as polymer, surfactant, micro-bubbles, a combination thereof, and/or using a second fluid having an elevated temperature as compared to the temperature of the first fluid, may be used to achieve much greater drag reduction as well as lower dissipation rates than previously possible. The second fluid is ejected using a convex Coanda surface (7) and at a controlled velocity that is a small fraction of the velocity of the first fluid moving along the wall so that the flow lines of the second fluid are substantially aligned with the flow lines of the first fluid.

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: The invention provides a fluidic oscillator that is symmetrical about a longitudinal plane of symmetry (P), comprising an enclosure defining an oscillation chamber and having an inlet opening and an outlet opening through which the fluid flows and which are in alignment in said plane (P) in a “longitudinal” first direction (A), said inlet opening being made in the form of a slot that is narrow in a second direction (B) extending transversely to said plane (P) and elongate in a third direction (C) parallel to said plane (P) and perpendicular to said longitudinal first direction (A), wherein said slot is provided in an insert which is removable from said enclosure.

Abstract: In one embodiment, a fluidic module, such as a microfluidic module, has a fluid-flow channel, an electroosmotic flow membrane positioned in the channel, and a cathode located on one side and an anode located on the other side of the membrane so that an electrolyte in the channel is transported through the membrane in the presence of a voltage. In another embodiment, the channel has a port, a flexible and fluid-impermeable diaphragm is added, the electrolyte is contained in a reservoir, and the membrane moves the bladder which acts as a valve for fluid leaving the channel through the port. In a further embodiment, electrolyte in a first reservoir is transported through the membrane to move the bladder to force fluid out of a second reservoir.

Abstract: A diffuser (7) has a step (12) in the surface (9) just upstream of a point where boundary layer separation might occur. An acoustic jet (22) has a nozzle (17) immediately downstream of the step (12); the acoustic jet is driven (25) by a plurality of frequencies, one or more of which are subharmonics of another of them, and having different phases.

Abstract: A switching device for controlling fluid motion. The device includes a capillary filled with a first fluid into which a wall-confined bubble of a second fluid is introduced to achieve a first switching event. Capillary geometry and wetting properties provide a pressure-related asymmetric energy potential distribution for controlling the flow of the bubble, and the device is called an asymmetric bubble chamber, or ABC. The bubble is initially trapped in an energy potential well, and upon increase of its volume moves from the well into a region of low energy potential to achieve a second switching event. The first switching event may be blocking of a fluid channel or reflection of an optical beam in an optical crosspoint switch, while the second switching event may be unblocking of a fluid channel or restoration of transmission of an optical beam.

Abstract: The present invention provides multi-layer microfluidic systems, by providing additional substrate layers, e.g., third, fourth, fifth and more substrate layers, mated with the typically described first and second layers. Microfabricated elements, e.g., grooves, wells and the like, are manufactured into the surfaces between the various substrate layers. These microfabricated elements define the various microfluidic aspects or structures of the overall device, e.g., channels, chambers and the like. In preferred aspects, a separate microscale channel network is provided between each of the substrate layers.

Abstract: A fluid dynamic diverter valve is provided which has a valve body with a fluid inlet zone communicating with a fluid diversion zone, which in turn communicates with a fluid outlet zone. In the fluid inlet zone there is at least one inlet for a fluid, at least one air inlet and a venturi passage for guiding the fluid as a jet. In a passage downstream of the venturi passage the air inlet communicates with the fluid jet exiting the venturi passage and the jet enters the diversion zone. Depending on whether the air inlet is blocked or not, the fluid jet either continues straight through the diversion zone to a first outlet from the valve body or, if the air stream is blocked, the jet is diverted to impinge upon a wall in the diversion chamber, the wall being arranged to be directed toward a different one of the outlet openings in the fluid outlet zone.

Abstract: A method and apparatus for ejecting a second fluid into the near-wall region of the boundary layer of a first fluid, so that the second fluid hugs the wall. This alone reduces drag by modifying the behavior of the near-wall structure, thereby reducing the frequency of burst and sweep cycles, even when the first and second fluids are identical. Further, one or more additives, such as polymer, surfactant, micro-bubbles, a combination thereof, and/or using a second fluid having an elevated temperature as compared to the temperature of the first fluid, may be used to achieve much greater drag reduction as well as lower dissipation rates than previously possible. The second fluid is ejected using a convex Coanda surface (7) and at a controlled velocity that is a small fraction of the velocity of the first fluid moving along the wall so that the flow lines of the second fluid are substantially aligned with the flow lines of the first fluid.

Abstract: A modular subsystem of a fluidic system is formed by assembling a set of chemically etched sheets of material. The modular subsystem includes mechanical, electrical, and fluidic components. A plurality of sheet members is provided. Respective ones of the sheet members are etched to form portions of mechanical, electrical, and fluidic components. A set of the sheet members are attached to each other to form a modular subsystem comprising the mechanical, electrical, and fluidic components. The resulting modular subsystem is assembled from a set of chemically etched sheets of material, and comprises a set of sheet members attached to each other. Each sheet member within the set is etched so that the mechanical, electrical, and fluidic components are formed when the sheet members are attached to each other.

Abstract: The present invention provides multi-layer microfluidic systems, by providing additional substrate layers, e.g., third, fourth, fifth and more substrate layers, mated with the typically described first and second layers. Microfabricated elements, e.g., grooves, wells and the like, are manufactured into the surfaces between the various substrate layers. These microfabricated elements define the various microfluidic aspects or structures of the overall device, e.g., channels, chambers and the like. In preferred aspects, a separate microscale channel network is provided between each of the substrate layers.

Abstract: The invention relates to a fluidic oscillator that is symmetrical about a longitudinal plane of symmetry, the oscillator comprising an opening enabling a fluid to enter into an “oscillation” chamber in the form of a two-dimensional fluid jet oscillating transversely relative to said plane of symmetry, an obstacle occupying the major portion of said oscillation chamber and possessing a front wall provided with a cavity situated facing said opening and swept over by the fluid jet in oscillation, wherein two side walls extend on either side of the opening and form a nozzle inside the oscillation chamber extending towards the obstacle and having a longitudinal dimension that is less than the distance between the opening and the front wall of the obstacle.

Abstract: Methods of controlling fluid flow through microchannels by use of passive valves or stopping means in the microchannels is presented. The passive valves act as pressure barriers impeding flow of solution past the stopping means until enough force is built up to overcome the force of the pressure barrier. Well planned use of such stopping means acting as passive valves allows the flow of fluids through microchannels to be regulated so as to allow fluids to be mixed or diluted after being introduced via a single channel, or to be split into multiple channels without the need for individual pipetting. Flow through the multiple channels can be regulated to allow a series of sister wells or chambers to all fill prior to the fluid flowing beyond any one of the sister wells or chambers. The filling of sister wells or chambers in this manner allows all wells or chambers to undergo reactions in unison. The use of air ducts to prevent trapping of air in the microchannels is also presented.

Abstract: A fluidic oscillator includes a member having an oscillation inducing chamber, at least one source of fluid under pressure, at least a pair of power nozzles connected to the at least one source of fluid under pressure for projecting at least a pair of fluid jets into the oscillation chamber, and at least one outlet from the oscillation chamber for issuing a pulsating or oscillating jet of fluid to a point of utilization or ambient. A common fluid manifold connected to said at least a pair of power nozzles. The shape of the power nozzle manifold forms one of the walls of the interaction or oscillation chamber. In some of the fluidic circuits, the length can be matched to fit existing housings. The power nozzle can have offsets which produce yaw angles in a liquid spray fan angle to the left or right depending on the direction desired.

Abstract: Fluidic oscillators with yawed liquid spray.

Abstract: Skin friction reduction on a surface moving relative to a fluid can be obtained by ejecting a polymer-water mixture/solution into the boundary layer. The efficacy of the ejected polymer-water mixture/solution is closely related to polymer dissipation out of the boundary layer and conditioning (i.e, lenthening, unwinding or stretching) of the polymer molecules by liquid shear forces immediately before ejection. The invention is a method and apparatus for conditioning and ejecting a polymer-water mixture/solution that improves drag reduction characteristics of the mixture/solution and maintains the mixture/solution in the boundary layer for as long as possible. By improving the drag-reduction characteristic in the polymer-water mixture/solution and by extending the time it remains in the near-wall region, the ejector can increase the performance and reduce the volume and storage requirements of a drag-reduction system.

Abstract: The present invention relates to a railroad car brake manifold adapted to be attached to the pipe brackets on existing railroad cars to provide sufficient pneumatic chambers and channels to perform the required pneumatic logic flow for pneumatic devices attached to the manifold, accomplish pneumatic timing function and provide system stabilization for electronically controlled pneumatic braking systems.

Abstract: A microfabricated device and method for proportioning and mixing biological or chemical materials by pressure- or vacuum-driven flow is disclosed. The microfabricated device mixes a plurality of materials in volumetric proportions controlled by the flow resistances of tributary reagent channels through which the materials are transported. The microchip includes two or more tributary reagent channels combining at one or more junctions to form one or more mixing channels. By varying the geometries of the channels (length, cross section, etc.), a plurality of reagent materials can be mixed at a junction such that the proportions of the reagent materials in the mixing channel depend on a ratio of the channel geometries and material properties. Such an approach facilitates flow division on the microchip without relying on techniques external to the microchip.