Abstract: The invention relates to a substrate material for analyzing one or more fluid samples for the presence, amount or identity of one or more analytes in the samples, whereby the substrate material is adapted in that way that a flow of the sample or parts thereof in and/or with the substrate material is influenced and/or caused by phase transitions, preferably photoinducable phase transitions, in selected areas of the substrate material.

Abstract: Provided is a microfluidic control device and method for controlling the microfluid, and a fine amount of fluid is controlled even with natural fluid flow and solution injection, wherein a pressure barrier of a capillary is removed by a surface tension change resulted from the solution injection to thereby obtain transport, interflow, mixing, and time delay of the microfluid, and to detail this, solution is injected to meet the boundary surface of the stopped fluid when the fluid is stopped by the stop valve, so that a function of the stop valve is removed to obtain the transport, interflow, and mixing of the fluid, and the method for controlling the microfluid may be applied to the microfluidic control device for biochemical reaction, and it uses only the capillary force change resulted from solution injection to thereby have its structure simplified.

Abstract: Provided is an electrohydrodynamic (EHD) micro-pump and a method of operating the same. The EHD micro-pump includes a plurality of electrodes alternately disposed on a substrate, an insulating layer covering the electrodes on the substrate, a carbon nanotube (CNT) layer formed on the insulating layer, a cover that forms a chamber with the substrate to accommodate the plurality of electrodes on the substrate where the cover includes a fluid inlet and a fluid outlet, an upper electrode formed on an inner surface of the cover facing the plurality of electrodes, and a power supplier that applies a voltage to the plurality of electrodes.

Abstract: Low pressure off gases such as from dry gas seals may be recompressed to a higher pressure using multiple tandem supersonic ejectors in which upstream ejectors operate at a higher nozzle exit Mach number than down stream ejectors and all ejectors are operated at exit Mach numbers greater than 1.

Abstract: A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.

Abstract: The invention is directed to a method and device for routing, mixing, or reacting droplets or liquid microstreams along the surface of a flat substrate. The flow of liquid microstreams or microdroplets along designated pathways is confined by chemical surface patterning. Individually addressable heating elements, which are embedded in the substrate, can be used to generate flow via thermocapillary effects or to trigger or quench chemical reactions. The open architecture allows the liquid to remain in constant contact with the ambient atmosphere. The device can be used for microfluidic applications or as a surface reactor or biosensor, among other applications.

Abstract: A method of simply controlling the flow of fluid in a micro system without using a complicated value structure, comprising the steps of adding the substance transformed from sol-gel by stimulation to the fluid flowing through the micro flow passage of the micro system, and adding the stimulation to the fluid at a desired position on the micro flow passage to transform the fluid into gel for flow control.

Abstract: The invention relates to an electrically-opened micro fluid-valve. The inventive valve comprises: at least one planar support (12); at least one afferent microchannel (14); at least one efferent microchannel (16), said microchannels being arranged in the support (12); such that at least one of the ends (141 and 161) thereof touch the inner face (121) of the support close to one another; at least one deposit (18) of a heat-sensitive material which is disposed on the inner face (121) of the support (12); and at least one heating means (20). According to the invention, the aforementioned deposit (18) of heat-sensitive material at least partially seals the space separating the ends (141 and 161) of the microchannels (14 and 16), thereby preventing same from intercommunicating.

Abstract: The present invention is directed to methods of controlling the flow of fluids through a microfluidic circuit and, more particularly, to methods of controlling the movement of fluid through a microfluidic circuit using one or more triggerable passive valves. In one embodiment of a method of controlling the flow of fluids through a microfluidic circuit according to the present invention, the microfluidic circuit includes a triggerable valve in series with a passive valve. In a further embodiment of a method of controlling the flow of fluids through a microfluidic circuit according to the present invention, the microfluidic circuit includes first and second triggerable valves in parallel.

Abstract: A relay long in service life aiming at higher reliability and lower cost is achieved by use of a technology of microelectromechanical•systems. The relay comprises a flow path having narrow chokes and wide chokes, formed by bonding two insulating members together, a plurality of liquid chambers formed by partitioning the flow path with the narrow chokes and the wide chokes, a plurality of electrodes disposed at the plurality of the liquid chambers, respectively, first and second gas chambers disposed so as to communicate with respective ends of the flow path, a gas sealed in the first and second gas chambers, respectively, heating means for heating the gas, and holes defined in one of the insulating members, communicating with the flow path, respectively, wherein a conductive fluid is introduced into the flow path through respective inlet ports of the holes, and the respective inlet ports are sealed.

Abstract: A microfluidic system includes a bubble valve for regulating fluid flow through a microchannel. The bubble valve includes a fluid meniscus interfacing the microchannel interior and an actuator for deflecting the membrane into the microchannel interior to regulate fluid flow. The actuator generates a gas bubble in a liquid in the microchannel when a sufficient pressure is generated on the membrane.

Abstract: A liquid transportation device includes a working board, a working liquid, a liquid channel and a cover board, wherein the liquid channel is formed on a top surface of the working board, the covering board is fully covered the liquid channel, the liquid channel composed of a material substantially tending to the liquid, and the covering board is composed of a material substantially phobic to the liquid. The working liquid flows within the liquid channel in guidance of the deviation of surface tension between the liquid channel to the working liquid, and the covering board to the working liquid, so that the working liquid is transported within the liquid channel without any external power.

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: Microfluidic devices provide substances to a mass spectrometer. The microfluidic devices include first and second surfaces, at least one microchannel formed by the surfaces, and an outlet at an edge of the surfaces which is recessed back from an adjacent portion of the edge. Hydrophilic surfaces and/or hydrophobic surfaces guide substances out of the outlet. A source of electrical potential can help move substances through the microchannel, separate substances and/or provide electrospray ionization.

Abstract: An airbag inflation apparatus includes a chamber for generating a gas to inflate an airbag. A valve, including a magnetic fluid and a source of magnetic field, preferably an electromagnet, is associated with the chamber for regulating the flow of the gas into the airbag. A sensor determines and feeds occupant information to the sensor.

Abstract: A method of fabricating an elastomeric structure, comprising: forming a first elastomeric layer on top of a first micromachined mold, the first micromachined mold having a first raised protrusion which forms a first recess extending along a bottom surface of the first elastomeric layer; forming a second elastomeric layer on top of a second micromachined mold, the second micromachined mold having a second raised protrusion which forms a second recess extending along a bottom surface of the second elastomeric layer; bonding the bottom surface of the second elastomeric layer onto a top surface of the first elastomeric layer such that a control channel forms in the second recess between the first and second elastomeric layers; and positioning the first elastomeric layer on top of a planar substrate such that a flow channel forms in the first recess between the first elastomeric layer and the planar substrate.

Abstract: An apparatus for dividing the flow of a gas stream and a method for controlling the flow division of a gas stream are disclosed, the apparatus including an inlet conduit for receiving the gas stream, outlet conduits in fluid communication with the inlet conduit for delivering the gas stream, a balancing gas feed conduit in fluid communication with an outlet conduit, a balancing gas feeder in fluid communication with the balancing gas feed conduit, and a balancing gas controller; and the method including the steps of dividing the process gas stream into process gas stream fractions and injecting a balancing gas stream into a process gas stream fraction in an amount sufficient to displace a portion of gas flow from the process gas stream fraction into one or more remaining process gas stream fractions.

Abstract: A method and flow system for controlling the flow of a liquid in a flow system, the liquid flow comprising particles and being led into a channel thereof. The method comprises the steps of enveloping the liquid flow by a flow of carrier liquid, hydrodynamically focussing the particles in the liquid flow providing a measurement signal of the liquid flow from an observation area in the channel, and dividing the liquid flow at a branching point into two or more outlets in response to the measurement signal. The division of the liquid comprises introducing a control liquid from at least one control channel at a merging point or merging area in the channel. The amount of control liquid is controlled by at least one electro-kinetic pump, the pump effect of which is controlled in response to the measurement signal.

Abstract: Microfluidic devices with multiple fluid process regions for subjecting similar samples to different process conditions in parallel are provided. One or more common fluid inputs may be provided to minimize the number of external fluid supply components. Solid materials such as chromatographic separation media or catalyst media is preferably provided in each fluid process region. Solid materials may be supplied to the devices in the form of slurry, with particles retained by porous elements or frits. Different fluid process regions may having different effective lengths, different solid material types or amounts, or may receive different ratios of common fluids supplied to the device. The flow resistances of dissimilar fluid process regions may be balanced passively with the addition of impedance elements in series with each fluid process region.

Abstract: A microfluidic system includes a bubble valve for regulating fluid flow through a microchannel. The bubble valve includes a fluid meniscus interfacing the microchannel interior and an actuator for deflecting the membrane into the microchannel interior to regulate fluid flow. The actuator generates a gas bubble in a liquid in the microchannel when a sufficient pressure is generated on the membrane.

Abstract: A device for interrupting or throttling undesired ionic transport through a fluid network is disclosed. The device acts as a fluid valve by reversibly generating a fixed “bubble” in the conducting solvent solution carried by the network. The device comprises a porous hydrophobic structure filling a portion of a connecting channel within the network and optionally incorporates flow restrictor elements at either end of the porous structure that function as pressure isolation barriers, and a fluid reservoir connected to the region of the channel containing the porous structure. Also included is a pressure pump connected to the fluid reservoir. The device operates by causing the pump to vary the hydraulic pressure to a quantity of solvent solution held within the reservoir and porous structure. At high pressures, most or all of the pores of the structure are filled with conducting liquid so the ionic conductance is high.

Abstract: Disclosed is a micro flowguide device comprising: a micro channel comprising at least one bubble trap to retard bubbles positioned in said bubble trap; an electrolytic bubble generating device to generate bubbles in said fluid by an electrolytic reaction; and a pressure source to supply a suited pressure to said fluid to pass through said micro channel; wherein said electrolytic bubble generating device causes bubbles to be generated at areas adjacent to said at least one bubble trap. Electrolytic bubbles are generated through a, localized electrolytic reaction enabled by the exposure of a set of DC-source-connected electrodes inside a conduit branch. Accumulated bubbles will be trapped and kept at several traps of the invented flowguide. When the backward pressure of trapped bubbles is rising to the level of forward pressure head, flow speed reduces to zero and channel branch is shut down.

Abstract: A fluidic valve (125, 300, 500, 900, 1000, 1100, 1200, 1300) switches a state of flow of a fluid in a fluid communication channel of a fluid guiding structure (505). Heating a bi-phase valve element (515, 1065, 1215) causes a change a state of the bi-phase valve element from a high viscosity state to a low viscosity state. A bi-phase valve element that clogs the fluid communication channel can be pushed into an expanded portion (135, 320, 520, 915, 1220) of the fluid communication channel by an application of pressure to the fluid while the bi-phase valve element is in the low viscosity state, unclogging the fluid communication channel. A bi-phase valve element can be pushed from a valve element source chamber (550, 1250) into the fluid communication channel by using a pumped fluid entering the source chamber at a pump inlet (551) while the bi-phase valve element is in the low viscosity state, clogging the fluid communication channel.

Abstract: With a method of controlling the flow in a flow system where a liquid flow contains a particle concentration, the liquid flow is surrounded by a carrier liquid. The liquid flow and carrier liquid are led into a central channel in which there is provided an observation area (4) where measurements of the liquid flow are effected. The result of the measurements are used to lead the liquid flow into one of several channels, in that control liquids are introduced into the liquid flow before this reaches the channels, the control liquids being derived from a capillary pump structure which pumps on the basis of an electro-kinetic effect, e.g. an electro-osmotic effect. In a preferred embodiment, the pump structure consists of two capillary structures, to each of which an electrical field can be applied. Depending on the strength of the field, the amount of control liquid will be able to be controlled so that the liquid flow with the particle concentration can be led to one of two channels.

Abstract: A microfluidic system is provided for controlling delivery and mixing of thermally-responsive fluids. A plurality of microfluidic inlet channels open into a mixing chamber. A valve is associated with each of the inlet channels for controlling the flow of the thermally-responsive fluids through the inlet channels. The valves include a heater in thermal contact with at least a portion of the associated inlet channel, whereby the viscosity of the thermally-responsive fluids can selectively be controlled by heat to cause a change in flow of the thermally-responsive fluids through the inlet channels. A plurality of microfluidic outlet channels may be provided for transporting mixed fluids from the mixing chamber. A valve associated with each of the outlet channels controls the flow of the mixed thermally-responsive fluids through the outlet channels.

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 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 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 method of controlling flow of a driven fluid in a channel, the channel being defined by an encircling wall, the method comprising the steps of sealing the channel with a sealing fluid immiscible in the driven fluid blocking the channel at an initial position, in which the sealing fluid has a first contact angle with the encircling wall and the driven fluid has a second contact angle with the encircling wall and the first contact angle is less than the second contact angle; and moving the sealing fluid in the channel by a force generated outside of the channel.

Abstract: A microfluidic valve for controlling the flow of a material through a microfluidic channel comprising: a) a microfluidic channel comprising a passageway, b) a heater in contact with at least a portion of the microfluidic channel, c) a carrier fluid comprising the material and an amount of thermally-responsive material so that the carrier fluid can be thickened by heat from the heater to cause a reduction in flow of the carrier fluid through the microfluidic channel.

Abstract: A valve (1) on the basis of electrorheological and/or magnetorheological fluids includes a fluid inlet channel (3) connected through a valve gap (5) to a fluid outlet channel (4). The valve gap is filled with an electrorheological and/or magnetorheological fluid and is bounded by bounding surfaces that are embodied as electrically energizable capacitor electrodes and/or coil arrangements, whereby the field excitation thereof acts on the fluid flowing through the valve gap. At least one bounding surface of the valve gap is embodied to be movable selectively toward and away from another bounding surface, so as to superimpose a squeeze mode and a flow mode of the electrorheological and/or magnetorheological effect. The valve gap may define a meandering or spiral flow path for the fluid. In this manner, a compact valve can provide high blocking pressures and high through-flow rates.

Abstract: Micro-fluid devices and methods for their use are provided. The subject devices are characterized by the presence of at least one micro-valve comprising a phase reversible material, e.g. a reversible gel, that reversibly changes its physical state in response to an applied stimulus, e.g. a thermoreversible gel. In using the subject device, fluid flow along a flow path of the device is modulated by applying an appropriate stimulus, e.g. changing the temperature, to the microvalve. The subject devices find use in a variety of applications, including micro-analytical applications.

Abstract: A monolithic flow controller for controlling the rate at which a medicinal liquid is administered to a patient. The monolithic flow controller includes one or more virtual valves that, because of their relatively small opening size (less than 0.5 &mgr;m in diameter), only permit fluid to flow through the valve when a forward bias voltage is applied. If a reverse bias voltage or no voltage is applied, fluid flow through the opening is inhibited. The fluid rate through the device is monitored using two pressure sensors or a differential pressure sensor that determine the differential pressure along the flow path through the device or relative to the external ambient pressure. The flow through the device is equal to the product of the differential pressure and the conductance of the channel in the flow controller. A capacitive bubble sensor is optionally provided to detect bubbles in the medicinal liquid being administered to the patient.

Abstract: The present invention provides a use of an electro-sensitive movable fluid, that is, a micromotor, a linear motor, a micropump and a method of using the micropump, a microactuator, and an apparatus which these devices are applied to, and a method and an apparatus of controlling flow properties of a fluid.

Abstract: A method and system for controlling the flow of a gaseous medium through a fluid are described. The method includes providing a rheologic fluid through which a gaseous medium can be conducted, and controlling the viscosity of the rheologic fluid to control the flow of the gaseous medium. The system has a rheologic fluid, which is located in particular in a device to be controlled, a guide guiding the gaseous medium through the fluid, and a field applier for applying a field at least partially in the area of the rheologic fluid.

Abstract: A controllable valve assembly (18) applicable in Magnetorheological (MR) fluid devices (20), such as MR mounts and MR dampers. The valve assembly (18) includes a valve body (32) having a magnetic circuit (40) contained therein which carries magnetic flux .phi., a controllable passageway (42) within the magnetic circuit (40), a MR (magnetically controlled) fluid (44) including soft-magnetic particles in a liquid carrier contained in the controllable passageway (42), a magnetic flux generator, such as a wound wire coil (46), generating magnetic flux .phi. which is directed through the MR fluid (44) in the controllable passageway (42) thereby generating "rheology" changes causing restriction in flow of MR fluid (44) therethrough.

Abstract: Microdevices based on surface tension and wettability are useful as sensors, detectors, actuators, pumps, among other applications. As sensors and detectors they can respond to numerous stimuli such as pressure, temperature, gravity, rotation, acceleration, oscillation, chemical environments, magnetic fields, electric fields, radiation, and particle beams with a great choice of output options. Because of their design, they can be used in a broad range of temperatures and environments. Additionally, unlike other microsensors and detectors, these devices can be exposed to forces and pressures orders of magnitudes greater than their design limit and still return to their original accuracy and precision. These microdevices are also useful as actuators, pumps, valves and shutters. It is possible by joining these devices together to form complex devices that are able to control macroscopic flows for example. They are also able to perform complex electrical switching operations.

Abstract: A microfabricated device and method for electrokinetic transport of a liquid phase biological or chemical material is described. In accordance with one aspect of the present invention there is provided a microchip that is adapted for the simultaneous spatial confinement of electrokinetically driven fluidic material streams on a substrate. The apparatus includes a focusing chamber formed in a surface of the substrate and in fluid communication with two sample fluid channels and three focusing fluid channels. The device further includes electromotive means operatively connected to the sources of the sample fluid and the source of focusing fluid for electrokinetically driving the respective streams of the sample and focusing fluids through the respective channels into the focusing chamber such that the focusing fluid streams spatially confine the first and second sample fluid streams within the focusing chamber.

Abstract: The invention relates to a lubrication system for a mechanism (27), on-board a spacecraft. It comprises a non pressurized tank (20) communicating with the mechanism (27) via a tube (220). A piston (23) closes the tube (220) while the mechanism is at rest. The piston (23) is controlled by a first spring (5) and by a second, shape memory, spring (24) opposing the latter, which lengthen by thermal effect. A controller (25, 26) supplies this spring with a current (I) to actuate it. An annular element(7), pushed by a cylindrical spring (6), defines a capillarity filled pumping chamber (22). When the temperature of the shape memory alloy (24) falls back below a threshold, the spring (24) recovers its original shape, the first spring (5) pushes back the piston (23) and expels a dose of lubrication fluid (4).

Abstract: A gas flow valve comprises at least one gas inlet, at least one gas outlet, a flow path between said gas inlet and said gas outlet, a magnetic fluid in the valve arranged in the flow path and means for application of a magnetic field to the magnetic fluid. The magnetic fluid solidifies upon application of the magnetic field, interrupts the flow path from at least one gas inlet to at least one gas outlet gas-tight and permits gas flow when no magnetic field is applied.

Abstract: In the present invention, various sizes of non-wetting droplets are inserted into microtube devices of various shapes having therein a gas or wetting fluid which causes the droplets to movement in response to fluid pressure. The droplets may translate within a void of the microtube device which is filled with the gas or wetting fluid or rotate in a fixed position. The nonwetting fluid may also be formed into rings within ring shaped channels. The microtube devices may operate to stop fluid flow, act as a check-valve, act as a flow restrictor, act as a flow regulator, act as a support for a turning axle, and act as a logic device, for example.

Abstract: Improved methods of displacing a first liquid through a pipe with a second liquid while preventing the first and second liquids from mixing are provided. In accordance with the methods, a plug is formed in-situ in the pipe between the first and second liquids by injecting a self-thickening liquid therein and permitting the liquid to thicken. The formed plug and the first liquid are then displaced through the pipe with the second liquid. The methods are particularly suitable for carrying out subterranean well bore cementing operations wherein cement slurries are displaced through pipes disposed in well bores.

Abstract: An apparatus for dispensing a cryogenic liquid includes means for focusing a beam of energy, eg. laser energy from a source onto the liquid cryogen as it passes through an outlet from a cryogenic liquid container.

Abstract: A valve used to control the flow of a magnetorheological fluid, in which the mechanical properties of the magnetorheological fluid are varied by applying a magnetic field, is described. The valve can comprise a magnetoconducting body with a magnetic core that houses an induction coil winding, and an hydraulic channel located between the outside of the core and the inside of the body connected to a fluid inlet port and an outlet port, in which magnetorheological fluid flows from the inlet port through the hydraulic line to the outlet port. Devices employing magnetorheological valves are also described.

Abstract: The invention features a needle defining a flowpath, a housing comprising a proximal end and a distal inner seat leading to and defining a lumen, and a viscous material contained within the housing. The needle is slidable through the housing and the viscous material contained therein. The viscous material is fluid enough for the needle to slide therethrough, yet semi-solid enough to conform to the housing distal inner seat so as to form a seal thereat and prevent flow of fluid or air through the lumen.

Abstract: The invention provides a pressure noise suppression system which includes a fluid input circuit 22 for receiving pressure pulses carried by a first fluid which is displaceable; a fluid vessel 10 having a non-linear tube 28 containing a second fluid; a signal generator 18 for transmitting pressure pulses carried by the first fluid for displacing the second fluid; a fluid output circuit 36 having a displaceable third fluid; and a pressure sensor 38 for sensing pressure impulses which pass through the second fluid.

Abstract: A control apparatus for an electroviscous fluid has a pair of electrodes between which the electroviscous fluid is disposed and a control device for applying nearly-trapezoidal shaped pulses positive and negative voltages alternately across the electrodes to control viscosity of the electroviscous fluid. The control apparatus changes gradually a voltage value when switching between the positive voltage and the negative voltage.

Abstract: A valve used to control the flow of a magnetorheological fluid, in which the mechanical properties of the magnetorheological fluid are varied by applying a magnetic field, is described. The valve can comprise a magnetoconducting body with a magnetic core that houses an induction coil winding, and an hydraulic channel located between the outside of the core and the inside of the body connected to a fluid inlet port and an outlet port, in which magnetorheological fluid flows from the inlet port through the hydraulic line to the outlet port. Devices employing magnetorheological valves are also described.

Abstract: An E-R hydraulic control valve that has two or more surfaces that can be moved relatively to one another to adjust a flow orifice size while maintaining a control voltage gradient across the E-R fluid and to seat one surface against the other to shut off fluid flow. Combining movable mechanical fluid flow elements with E-R fluid control allows initial tuning of the valve to a particular application by mechanical restriction of an orifice, and E-R operating control of the fluid. Seating the mechanical surfaces provides a fail-safe shut-down mode.

Abstract: A pressure regulating inlet-and-outlet valve for a sealed space enclosed by a housing wall (10). The wall is penetrated by at least one gap (6) that is spanned by a magnetic field and completely occupied by a ferrofluidic liquid (7) confined inside the gap by the field.