Abstract: In a lubricant-cooled gas compressor (10) the temperature of separated lubricant returned to the air-side (11) is monitored by a thermostatically controlled restrictor valve (22) which minimises the flow of returned lubricant when temperature is low as on start up or when running on reduced load but increases the flow as the lubricant temperature increases. This will minimise he condensation of water from indrawn air when the temperature of the compressed air is too low to retain the water as vapour, so that the returned lubricant is contaminated with water which will damage the moving components of the air-end.

Abstract: The invention relates to a method of controlling flow of liquids in a micro channel structure. It comprises providing in said micro channel structure plugs (34) of polymer material in said structure, said polymer material in a first state blocking said channel from liquid flow, and in a second state providing a free path-way (32) for liquid flow. Energy is selectively applied so as to cause said polymer to enter a desired one of said first or second states. It also relates to a micro channel valve system, comprising a plurality of such plugs (34). Additionally it comprises a chemical reactor, comprising a plurality of micro chambers interconnected by micro channels, having a valve system according to the invention.

Abstract: In one embodiment of the present invention, a shape memory alloy (“SMA”)-actuated flow controller comprises a number of grille members, each having a long axis and being slideable relative to one another parallel to that long axis. The SMA-actuated flow controller also includes a frame configured to guide the number of grille members, and an actuator disposed within the frame to move at least one of the number of grille members for varying a size of an aperture. Further, the actuator includes an SMA actuator that includes a number of SMA elements each connecting one grille number to another.

Abstract: The present invention relates to a valve having a base body with a passage opening, a movable valve member for closing and opening the passage opening and an actuating mechanism for moving the valve member in order to open the passage opening. The actuating mechanism has at least two elements made from a shape memory alloy which are secured to the base body or a carrier body connected thereto, and can be alternately shortened in the event of the temperature rising above a threshold temperature and are connected to the valve member in such a way that the valve member can be moved from a position on the passage opening into a position alongside the passage opening when one element is shortened on one side and can be moved back into the position on the passage opening when the other element is shortened on one side.

Abstract: An apparatus controls flow of a fluid from at least one inlet port to at least one outlet port. A support has a rigid, non-flexible portion, at least one pivotable relatively rigid, non-flexible, folded-back arm portion extending from the rigid portion, at least one surface connected to folded-back arm portion for movement relative to the support, and a rigid, non-flexible force transfer member operably positioned for driving the pivotable folded-back arm portion with a loss of motion of less than 40%. An electrically operated actuator operably engages between the rigid portion and the force transfer member to pivot the folded-back arm portion in response to an electrical activation of the actuator. A manifold includes a fluid passage communicating with at least one valve seat and operably engageable with respect to at least one corresponding valve body for movement between a closed position and an opened position.

Abstract: Low power integrated pumping and valving arrays which provide a revolutionary approach for performing pumping and valving approach for performing pumping and valving operations in microfabricated fluidic systems for applications such as medical diagnostic microchips. Traditional methods rely on external, large pressure sources that defeat the advantages of miniaturization. Previously demonstrated microfabrication devices are power and voltage intensive, only function at sufficient pressure to be broadly applicable. This approach integrates a lower power, high-pressure source with a polymer, ceramic, or metal plug enclosed within a microchannel, analogous to a microsyringe. When the pressure source is activated, the polymer plug slides within the microchannel, pumping the fluid on the opposite side of the plug without allowing fluid to leak around the plug. The plugs also can serve as microvalves.

Abstract: A gating apparatus for controlling the gap between two surfaces that includes an upper structure having a polished central region portion, an elastically deformable fulcrum structure, and an elastically deformable lever region. The upper structure can be fabricated from silicon using microelectromechanical system (MEMS) fabrication techniques. The gating apparatus also includes a lower structure coupled to the upper structure at the elastically deformable fulcrum structure. The upper structure, in response to a force, can bend about the fulcrum structure, thereby forming a variable gap between the polished central region portion and the lower structure. The variable gap can be used as a filter to filter fluids and mixed phase fluids. The structures can be made from a wide variety of materials including silicon, glass, ceramic, metal, and plastic.

Abstract: The present invention provides a proportional microvalve having a first, second and third layer, and having high aspect ratio geometries. The first layer defines a cavity with inlet and outlet ports. The second layer, doped to have a low resistivity and bonded between the first and third layers, defines a cavity having a flow area to permit fluid flow between the inlet and outlet ports. The second layer further defines an actuatable displaceable member, and one or more thermal actuators for actuating the displaceable member to a position between and including an open and a closed position to permit or occlude fluid flow. The third layer provides one wall of the cavity and provides electrical contacts for electrically heating the thermally expandable actuators. The thermal actuators and the displaceable member have high aspect ratios and are formed by deep reactive ion etching such that they are displaceable in the plane of the second layer while being very stiff out of the plane.

Abstract: A microelectromechanical device wherein the displacement of an electrothermally compliant actuator is perpendicular to a mounting substrate allowing in a first embodiment a fluid control valve to be opened and closed and in a second embodiment a plurality of electrical contacts to be opened and closed. The electrothermally compliant actuator is comprised of a pair of beam structures having a joined thick beam and then beam such that a flow of electrical current causes the beam structures to bend. A flexible isolation layer is used to thermally isolate the electrothermally compliant actuator from the fluid in another valve assembly embodiment.

Abstract: A microvalve having a generally planar plate valve body defining a chamber and a plate valve member movable in the chamber about a pivot axis that is perpendicular to the valve body to control the flow of a fluid through the valve body. The plate valve member defines a pair of opposite faces, a first duct therethrough provides fluid communication between the opposite faces to equalize fluid pressures acting on the opposite faces in the region of the first duct. The plate valve member also has a second duct therethrough that provides fluid communication between the opposite faces to equalize fluid pressures acting on the opposite faces in the region of the second duct. The first duct and the second duct are equidistant from the pivot axis.

Abstract: A temperature sensitive valve (10) includes a body (11) affording a passageway (12) for fluid, a valve member (15) which is moveable relative to the body (11) between first and second positions to control the flow of fluid through the passageway (12), a retaining member (24) movable with the valve member (15) and being engageable with a holding device (21) to retain the valve member (15) in the first position whilst the temperature is below a threshold value, and there being a release actuator (30) movable when the temperature is at the threshold value to disengage the retaining member (24) and holding device (21), to permit the valve member (15) to move from the first to the second position.

Abstract: A bubble-actuated valve with latching may be utilized to regulate fluid flow in any number of applications, including the controlled delivery of drugs or other bioactive agents or compounds. The bubble-actuated valve utilizes the bubble to move a solid object that does the actual blocking of the flow channel to regulate the flow of liquid through the valve. The bubble-actuated valve may also include a latching mechanism. One such latching mechanism utilizes the capillary attraction between the solid object and neighboring walls to latch the solid object in place when the valve is not actuated.

Abstract: A zinc-air battery and control valve for controlling air flow to energize the battery. Telescoping inner and outer valve sleeves each have a plurality of openings that when aligned communicate air from the exterior to the interior of the valve. Two actuators are provided, one to open the valve and the other to close it. All of the openings are opened or closed simultaneously by sliding motion of the valve sleeves that fit concentrically together. A bistable latching mechanism is provided to keep the valve in either of its two positions. A pair of switches operate in coordination with the latching mechanism so that a closed circuit is established for changing the state from that which was last established.

Abstract: Valve with a displaceable actuating device that controls the movements of at least one actual sealing element for opening and closing, and the actuating device is loaded with an elastic element essentially in a perpendicular direction relative to the direction of displacement, and the longitudinal axis of the actuating device and the force exercised by the elastic element are aligned in one position of the actuating device between its two extreme positions. In order to realize a valve that can be electrically switched using minimal currents and that is characterized, in particular, by its small construction size but that is still able to achieve large regulating distances, the actuating device is a unilaterally constrained piezoelectric bending element.

Abstract: An actuator assembly and method for making and using an actuator assembly. In one embodiment, the assembly includes an actuator body having an actuator channel with a first region and a second region. An actuator is disposed in the actuator channel and is movable when in a flowable state between a first position and a second position. A heater is positioned proximate to the actuator channel to heat the actuator from a solid state to a flowable state. A source of gas or other propellant is positioned proximate to the actuator channel to drive the actuator from the first position to the second position. The actuator has a higher surface tension when engaged with the second region of the channel than when engaged with the first region. Accordingly, the actuator can halt upon reaching the second region of the channel due to the increased surface tension between the actuator and the second region of the channel.

Abstract: A micro valve and a method for setting or actuating a micro valve for use in fluidic applications includes cooling an array of actuating members made of Shape Memory Alloy (SMA) material. The SMA material is cooled to a temperature equal to or below the temperature at which a transformation from austenitic to martensitic state occurs so that the entire array of SMA actuating members is either fully or partially in the martensitic state. At least one of the actuating member is selected to correspond to a pre-determined opening pressure or flow resistance. Each of the actuating members are heated individually, except the previously selected one, to a temperature equal to or above the temperature at which a transformation from the martensitic state to the austensitic state occurs.

Abstract: A one-shot, electro-pneumatic actuator apparatus for quickly supplying a pressurized fluid to an external device upon the actuation of an external control signal. The actuator includes a housing having a first portion for containing a quantity of pressurized fluid, a second portion having a reduced, cross-sectional area, and a third portion. The second portion includes a sealing element disposed therein for containing the pressurized fluid held in the first housing portion. A coil is wound around the second housing portion and receives a signal from an external control subsystem which causes the coil to heat the second housing portion, and thus the sealing element, to damage the sealing element. This enables the pressurized gas to escape through the second portion into the third portion of the housing and subsequently to the external device being controlled.

Abstract: A microvalve and a method of forming a microvalve. The microvalve comprises first and second layers, a diaphragm member and a switching means. The first and second layers are secured together to form a valve body that forms an inlet opening for receiving fluid, an outlet opening for conducting fluid from the valve body, and a flow channel for conducting fluid from the inlet to the outlet. The diaphragm is disposed between the layers, and is movable between open and closed positions. In these position, the diaphragm, respectively, allows and blocks the flow of fluid from the inlet to the flow channel. The diaphragm is biased to the closed position, and moves from the closed position to the open position when the pressure of fluid in the inlet reaches a preset value. The switching means is connected to the valve body for moving the diaphragm to the closed position against the pressure of fluid in the inlet.

Abstract: A microvalve device for controlling fluid flow in a fluid circuit. The microvalve device comprises a body having a cavity formed therein. The body further has first and second pilot ports placed in fluid communication with the cavity. The body also has first and second primary ports placed in fluid communication with the cavity. Each port is adapted for connection with a designated fluid source. A pilot valve supported by the body is movably disposed in the cavity for opening and closing the first and second pilot ports. An actuator is operably coupled to the pilot valve for moving the pilot valve. A microvalve is positioned by the fluid controlled by the pilot valve. The microvalve is a slider valve having a first end and a second end. The slider valve is movably disposed in the cavity for movement between a first position and a second position. The first end of the slider valve is in fluid communication with the first and second pilot ports when the first and second pilot ports are open.

Abstract: A proportional valve is disclosed for controlling the outlet pressure of a fluid flowing therethrough. The valve comprises a valve body having an inlet port and an outlet port for the fluid. The valve also has an inner chamber, within which there is formed a valve seat that may be opened and closed variably by a shutter axially movable from and towards the valve seat. Movement of the shutter is controlled by a shape memory alloy (SMA) actuating member operating antagonistically to an elastic member, the temperature of the fluid being lower than the transition temperature of the shape memory alloy. The actuating member and the elastic member are connected to the body valve at opposite sides relative to the valve seat. A power control circuit is also provided for circulating an electric current through the actuating member so as to heat the same by Joule effect from a temperature lower than the transition temperature to one that is higher.

Abstract: A shut-off valve assembly for regulating the flow of fluid through or from a fluid line The assembly comprises: a body attachable to or within a fluid line and having a chamber therein with inlets and an outlet for fluid from the fluid line; a valve seat that provides the outlet; a baffle arrangement including a baffle housing; a valve member having a sealing member movable between a shielded position, whereby the sealing member is substantially shielded by the baffle housing from a fluid stream moving from the inlets to outlet, and an unshielded position, whereby the sealing member can be forced by the fluid stream against the valve seat to seal the outlet; and a solenoid-spring drive for moving the sealing member between the shielded and unshielded positions.

Abstract: An actuator assembly and method for making and using an actuator assembly. In one embodiment, the assembly includes an actuator body having an actuator channel with a first region and a second region. An actuator is disposed in the actuator channel and is movable when in a flowable state between a first position and a second position. A heater is position proximate to the actuator channel to heat the actuator from a solid state to a flowable state. A source of gas or other propellant is positioned proximate to the actuator channel to drive the actuator from the first position to the second position. The actuator has a higher surface tension when engaged with the second region of the channel than when engaged with the first region. Accordingly, the actuator can halt upon reaching the second region of the channel due to the increased surface tension between the actuator and the second region of the channel.

Abstract: A microvalve and a method of forming a microvalve. The microvalve comprises first and second layers, a diaphragm member and a switching means. The first and second layers are secured together to form a valve body that forms an inlet opening for receiving fluid, an outlet opening for conducting fluid from the valve body, and a flow channel for conducting fluid from the inlet to the outlet. The diaphragm is disposed between the layers, and is movable between open and closed positions. In these position, the diaphragm, respectively, allows and blocks the flow of fluid from the inlet to the flow channel. The diaphragm is biased to the closed position, and moves from the closed position to the open position when the pressure of fluid in the inlet reaches a preset value. The switching means is connected to the valve body for moving the diaphragm to the closed position against the pressure of fluid in the inlet.

Abstract: The present invention relates to a miniaturized device controlled by electromagnetic signals in the radiofrequency range for controlled release of substances or for controlled sampling of specimens, comprising a reservoir, and a closing system associated to said reservoir, where said closing system is constituted by a valve structure, closing-opening of which is controlled by the electromagnetic signal in the radiofrequency range.

Abstract: A microfluidic device that includes a micro ball valve is provided. The microball valve is capable of preventing or interrupting fluid flow through the microfluidic device. The microfluidic device can include a substrate layer, and a microfluidic pathway that includes the microball valve. Methods are provided for manipulating fluids using the microfluidic device.

Abstract: A surface-micromachined mass flow controller (MFC) comprises an electrostatically actuated microvalve integrated with a thermal flow sensor. The microvalve comprises a normally-open diaphragm defining an aperture allowing fluid communication between first and second flow channels. The diaphragm includes a second electrode actuable toward a valve seat including a first electrode. Fabricated utilizing a multilayer Parylene process, the active microvalve and the flow sensor are integrated onto a single chip to perform closed-loop flow control. For flow control, both Pulse Width Modulation (PWM) and actuation voltage adjustment are demonstrated.

Abstract: A flexible area 2 is joined at one end via a thermal insulation area 7 to a semiconductor substrate 3 which becomes a frame and at an opposite end to a moving element 5. The thermal insulation area 7 is made of a thermal insulation material a resin such as polyimide or a fluoridated resin. The flexible area 2 is made up of a thin portion 2S and a thin film 2M different in thermal expansion coefficient. When a diffused resistor 6 formed on the surface of the thin portion 2S is heated, the flexible area 2 is displaced because of the thermal expansion difference between the thin portion 2S and the thin film 2M, and the moving element 5 is displayed with respect to the semiconductor substrate 3.

Abstract: A bubble-actuated valve with latching may be utilized to regulate fluid flow in any number of applications, including the controlled delivery of drugs or other bioactive agents or compounds. The bubble-actuated valve utilizes the bubble to move a solid object that does the actual blocking of the flow channel to regulate the flow of liquid through the valve. The bubble-actuated valve may also include a latching mechanism. One such latching mechanism utilizes the capillary attraction between the solid object and neighboring walls to latch the solid object in place when the valve is not actuated.

Abstract: A thermostat apparatus is provided. The thermostat apparatus comprises a thermostat and a positioner for establishing different operating temperatures for thermostat.

Abstract: The present invention provides a proportional microvalve having a first, second and third layer, and having high aspect ratio geometries. The first layer defines a cavity with inlet and outlet ports. The second layer, doped to have a low resistivity and bonded between the first and third layers, defines a cavity having a flow area to permit fluid flow between the inlet and outlet ports. The second layer further defines an actuatable displaceable member, and one or more thermal actuators for actuating the displaceable member to a position between and including an open and a closed position to permit or occlude fluid flow. The third layer provides one wall of the cavity and provides electrical contacts for electrically heating the thermally expandable actuators. The thermal actuators and the displaceable member have high aspect ratios and are formed by deep reactive ion etching such that they are displaceable in the plane of the second layer while being very stiff out of the plane.

Abstract: An actuator assembly and method for making and using an actuator assembly. In one embodiment, the assembly includes an actuator body having an actuator channel with a first region and a second region. An actuator is disposed in the actuator channel and is movable when in a flowable state between a first position and a second position. A heater is positioned proximate to the actuator channel to heat the actuator from a solid state to a flowable state. A source of gas or other propellant is positioned proximate to the actuator channel to drive the actuator from the first position to the second position. The actuator has a higher surface tension when engaged with the second region of the channel than when engaged with the first region. Accordingly, the actuator can halt upon reaching the second region of the channel due to the increased surface tension between the actuator and the second region of the channel.

Abstract: An actuator assembly and method for making and using an actuator assembly. In one embodiment, the assembly includes an actuator body having an actuator channel with a first region and a second region. An actuator is disposed in the actuator channel and is movable when in a flowable state between a first position and a second position. A heater is positioned proximate to the actuator channel to heat the actuator from a solid state to a flowable state. A source of gas or other propellant is positioned proximate to the actuator channel to drive the actuator from the first position to the second position. The actuator has a higher surface tension when engaged with the second region of the channel than when engaged with the first region. Accordingly, the actuator can halt upon reaching the second region of the channel due to the increased surface tension between the actuator and the second region of the channel.

Abstract: An SMA actuated miniature latching valve for on and off control of fluid flow. A valve closure includes a poppet for opening and closing the fluid flow path. The poppet is operated responsive to an actuator mechanism which has SMA wires arranged to be actuated by electric resistant heating. Actuation causes different ones of the wires to contract and pull the poppet either toward or away from a valve seat. A latching mechanism comprising a conical spring operates between two bistable positions which hold the poppet either fully open or fully closed without further application of power to the actuators. A method of forming a secure mechanical and electrical connection between an SMA wire end and its support includes the steps of swaging a metal cone between a cone-shaped hole in the support and the wire end.

Abstract: Devices for controlling the flow of fluid through plastic tubes, such as tubes which are part of a disposable blood donation tubing set are disclosed. The device has a clamp adapted for attachment with one or more other clamps to allow for easy flow control through two or more tubing segments.

Abstract: According to the present invention, there is provided a micro-fluidic sensor system (6) including a micro-conduit (56) for carrying fluid therethrough having a flexible wall portion (18), at least one micro-fluidic actuator having a closed cavity, flexible mechanism defining a wall of the cavity (11) and flexible wall portion (18) of the micro-conduit for deflecting upon an application of pressure thereto, and expanding mechanism (14) disposed in the cavity for selectively expanding the cavity and thereby selectively flexing said expanding mechanism, and sensor mechanism in fluid communication with the micro-conduit for sensing the presence or absence of molecules. The present invention further provides for a micro-fluidic system for moving micro-fluid amounts including a micro-conduit and at least one micro-fluidic actuator in fluid communication with the micro-conduit.

Abstract: A valve for the control of fluid flow in microsize systems, such as for transfer of small samples of blood for processing. An actuator beam comprised of a microribbon formed of a shape memory alloy is in a normally closed position where inlet and outlet ports of the valve are closed. In this position a compliant member presses against and holds the microribbon, together with a compliant tape carried below the microribbon, against the ports. The valve is actuated by heating the alloy through its crystalline phase change transition temperature. The resulting change of the microribbon to its memory shape moves the microribbon and tape away from the ports, enabling fluid flow through between the ports in a valve-open mode. The microribbon and tape are held in the valve-open mode when the alloy cools below the transition temperature by a force applied from a heat-shrinkable layer carried on the upper side of the microribbon.

Abstract: A microvalve and a method of forming a diaphragm stop for a microvalve. The microvalve includes a first layer and a diaphragm member to control the flow of fluid through the microvalve. The method comprises the step of forming a contoured shaped recess extending inward from a surface of the layer by using a laser to remove material in a series of areas, at successively greater depths extending inward from said surface. Preferably, the recess has a dome shape, and may be formed by a direct-write laser operated via a computer aided drawing program running on a computer. For example, CAD artwork files, comprising a set of concentric polygons approximating circles, may be generated to create the dome structure. The laser ablation depth can be controlled by modifying the offset step distance of the polygons and equating certain line widths to an equivalent laser tool definition.

Abstract: A valve for automatically modulating fluid flow includes a flexible flow adjustment member having a variable diameter passage therethrough and an outer surface and a shell surrounding at least a portion of the outer surface and creating a void between the shell and the outer surface. The shell is in contact with the flow of fluid. A thermally reactive material that expands when heated and contracts when cooled is a substantially non-volatile heat transfer liquid that does not undergo a phase change in use and contains inert particulate filler within the void and is in contact with the outer surface of the flexible flow adjustment member. The thermally reactive material exerts pressure on the adjustment member in response to heating the thermally reactive material to cause the passage to narrow and relieves pressure thereon in response to cooling the thermally reactive material to permit the passage to widen.

Abstract: A flow rate control valve includes a second substrate having a flexible thin film and interposed between a first substrate having a heating mechanism and a third substrate having a sealing section. The first substrate and the second substrate close an internal space formed adjacent to the heating mechanism and filled with an expandable material. The sealing section and the flexible thin film function together as a valve. The heating mechanism heats and expands the expandable material whose pressure is detected by pressure-detecting sensors. The detected pressure value is fed back to a control mechanism of the heating mechanism for opening/closing a fluid flow passage and controlling the valve opening degree.

Abstract: A multi-purpose valve includes, a band of a thermodynamic metal alloy with shape memory, with a memorised shape and a transition temperature which lies in the range for the normal body temperature of a mammal. The strip has a linear shape below the transition temperature and assumes the memorised shape above the transition temperature. The memorised shape is preferably a conical spiral with a closed tip, with the result that above the transition temperature range the valve will become a conical spiral.

Abstract: A microvalve with a normally closed state includes a membrane (80), an actuation means (100) for controllable deformation of the membrane (80) as well as a valve shutter (180) deformable by the controllable deformation of the membrane (80). The valve shutter (180) at least partially opposes the membrane (80) and rests, in a first position in the normally closed state of the valve, along a sealing lip (130) arranged between the valve shutter (180) and the membrane. The sealing lip (130) is arranged such that an outlet of the valve, which outlet is in fluid communication with an interrupted section of the sealing lip (130), is sealed against an input channel (170) bordering on the valve shutter (180). In addition, the valve shutter is moldable into a second position so as to bring the outlet (140) into fluidic communication with the input channel (170) in an open state of the valve.

Abstract: An actuator uses a gas absorptive material to produce displacement of a member of the actuator. In a described embodiment, an actuator includes a metal hydride powder. When the powder absorbs hydrogen gas, it expands and displaces a piston. When the powder discharges hydrogen gas, the powder contracts, displacing the piston in an opposite direction. Various methods of controlling gas absorption and discharge are provided.

Abstract: An actuator for controlling the flow of a fluid stream through a valve comprising a shape memory alloy element that positions a valve element to a first position when said SMA element is in an ambient temperature state and a second position when said SMA element is in an elevated temperature state, and a flow plate situated in the fluid stream in a position upstream of the SMA element and having a through-hole pattern to increase the velocity of fluid around the SMA element while it is in its elevated temperature state so as to cool the SMA element by fluid controlled by said valve and return the SMA element to its ambient temperature state.

Abstract: A valve can varied in operating pressure and stopped in opening and closing by an efficiently movable actuator due to feeding of electric power without malfunction due to disturbance of magnetism, impact or temperature. A variable pressure valve is provided with a shape memory alloy spring. The shape memory alloy spring is raised in temperature and varied in length by a secondary coil that is electromagnetically given power from a primary coil of a control probe. When the shape memory alloy spring varies in length, a feed ratchet performs linear movement to rotate a cam wheel. The cam wheel has a cam with which an urge spring and a rectifying lever at its one end is engaged. The urge spring and rectifying lever at their other ends engage a ball valve to vary an urge force on the ball valve due to rotation of the cam wheel.

Abstract: A microfluidic device that includes a micro ball valve is provided. The microball valve is capable of preventing or interrupting fluid flow through the microfluidic device. The microfluidic device can include a substrate layer, and a microfluidic pathway that includes the microball valve. Methods are provided for manipulating fluids using the microfluidic device.

Abstract: According to the present invention, there is provided a micro-fluidic valve including a micro conduit for carrying fluid therethrough and at least one micro actuating mechanism for selectively deflecting at least a portion of a wall of the micro conduit occluding fluid flow through the micro conduit. Additionally, the present invention provides for a mono-stable micro-fluidic valve and for a bi-stable micro-fluidic valve.

Abstract: An actuator assembly and method for making and using an actuator assembly. In one embodiment, the assembly includes an actuator body having an actuator channel with a first region and a second region. An actuator is disposed in the actuator channel and is movable when in a flowable state between a first position and a second position. A heater is positioned proximate to the actuator channel to heat the actuator from a solid state to a flowable state. A source of gas or other propellant is positioned proximate to the actuator channel to drive the actuator from the first position to the second position. The actuator has a higher surface tension when engaged with the second region of the channel than when engaged with the first region. Accordingly, the actuator can halt upon reaching the second region of the channel due to the increased surface tension between the actuator and the second region of the channel.

Abstract: A bistable microvalve of shape memory material is operatively connected to a microcatheter. The bistable microvalve includes a tip that can be closed off until it is in the desired position. Once it is in position it can be opened and closed. The system uses heat and pressure to open and close the microvalve. The shape memory material will change stiffness and shape when heated above a transition temperature. The shape memory material is adapted to move from a first shape to a second shape, either open or closed, where it can perform a desired function.

Abstract: An improved housing for a thermostatic valve has a nonconducting cover that features a projection into the interior of the valve housing. Mounted on the projection is a thermostatic operating element, which operates to control the valve when wax inside the thermostatic operating element is heated. A pair of electrical leads, connectable to an exterior power source, are embedded within the cover, extending through the projection and connecting to a heating element within the thermostatic operating element. When electrical current is applied to the heating element through the embedded electrical leads, the wax is heated, thereby expanding, driving a work piston of the thermostatic operating element, and opening the valve.

Abstract: A bistable microvalve of shape memory material is operatively connected to a microcatheter. The bistable microvalve includes a tip that can be closed off until it is in the desired position. Once it is in position it can be opened and closed. The system uses heat and pressure to open and close the microvalve. The shape memory material will change stiffness and shape when heated above a transition temperature. The shape memory material is adapted to move from a first shape to a second shape, either open or closed, where it can perform a desired function.