Abstract: A multilayer ceramic micropump including a monolithic ceramic package formed of a plurality of ceramic layers defining therein an integrated first ball check valve, and a second ball check valve in microfluidic communication with the first ball check valve, and an actuator characterized as actuating a pumping motion, thereby pumping fluids through the first ball check valve and the second ball check valve.

Abstract: A suspended p-GaN membrane is formed using photochemical etching which membrane can then be used in a variety of MEMS devices. In the illustrated embodiment a pump is comprised of the p-GaN membrane suspended between two opposing, parallel n-GaN support pillars, which are anchored to a rigid substrate below the pillars. The p-GaN membrane bows upward between the pillars in order to relieve stress built up during the epitaxial growth of membrane. This bowing substantially increases the volume of the enclosed micro-channel defined between membrane and substrate below. The ends of membrane are finished off by a gradual transition to the flat underlying n-GaN layer in which fluidic channels may also be defined to provide inlet and outlet channels to microchannel. A traveling wave or sequential voltage applied to the electrodes causes the membrane to deform and provide a peristaltic pumping action in the microchannel.

Abstract: A magnetohydraulic motor with a positive displacement pump that pumps hydraulic fluid to and from the two sides of a bi-directional piston that provides the motor's output force and motion. Motion control is provided by properly controlling valves that selectively open and close fluid passageways between the actuator member and each side of the piston.

Abstract: The fluidic drive for miniature acoustic-fluidic pump and mixer is comprised of an acoustic transducer attached to an exterior or interior of a fluidic circuit or reservoir. The transducer converts radio frequency electrical energy into an ultrasonic acoustic wave in a fluid that in turn generates directed fluid motion through the effect of acoustic streaming. Acoustic streaming results due to the absorption of the acoustic energy in the fluid itself. This absorption results in a radiation pressure and acoustic streaming in the direction of propagation of the acoustic propagation or what is termed “quartz wind”.

Abstract: A pump having a main pump body including a casing to which a fluid is supplied, and a pump section, an input valve section, and an output valve section which are provided opposingly to one surface in the casing. Each of the pump sections, the input valve section, and the output valve section has an actuator section. The input valve section, the pump section, and the output valve section are provided opposingly to the back surface of the casing for selectively forming a flow passage on the back surface of the casing in accordance with selective displacement action of the input valve section, the pump section, and the output valve section in a direction approaching or separating from the back surface of the casing. The fluid is controlled for its flow in accordance with the selective formation of the flow passage.

Abstract: A clearance between a rotor and a stator is adjusted by forming the outer peripheral surface of the rotor and the inner peripheral surface of the stator into a conical shape, and relatively moving the rotor and the stator in the thrust direction. When the rotor is rotatably supported by a magnetic bearing, the magnitude of the clearance between the rotor and the stator may be adjusted by offsetting the position at which the rotor is held in the thrust direction. The stator may be moved in the thrust direction by forming the bottom of the stator of electrostrictive material and expanding and contracting the electrostrictive member. When the outer peripheral surface of the rotor and the inner peripheral surface of the stator is cylindrical, the inner diameter of the stator may be increased and decreased by forming a part of the stator of electrostrictive material.

Abstract: An ultrasonic pump in which a medium is pumped by the interaction between longitudinal acoustic waves and the medium in a flow-chamber. The pump comprises a transducer and an associated chamber for providing a controllable, focused, acoustic traveling wave therein. The chamber includes a tapered passage corresponding to the focused beam pattern of the focused acoustic traveling wave through which the liquid medium flows and/or cavitation is induced and/or controlled. The pump therefore utilizes an acoustical transducer responsive to frequency input for directing longitudinal acoustic waves into the flow-chamber which induces a pressure gradient. The medium in the flow-chamber flows in the direction of travel of the acoustic wave in the chamber as a result of acoustic streaming. The exit orifice of the nozzle in communication with the chamber is strategically located at about the focal zone of the focused, traveling wave.

Abstract: An ultrasonic pump in which a medium is pumped by the interaction between longitudinal acoustic waves and the medium in a flow-chamber. The pump comprises a transducer and an associated chamber for providing a controllable, focused, acoustic traveling wave therein. The chamber includes a tapered passage corresponding to the focused beam pattern of the focused acoustic traveling wave through which the liquid medium flows and/or cavitation is induced and/or controlled. The pump therefore utilizes an acoustical transducer responsive to frequency input for directing longitudinal acoustic waves into the flow-chamber which induces a pressure gradient. The medium in the flow-chamber flows in the direction of travel of the acoustic wave in the chamber as a result of acoustic streaming. The exit orifice of the nozzle in communication with the chamber is strategically located at about the focal zone of the focused, traveling wave.

Abstract: An ultrasonic pump in which a medium is pumped by the interaction between longitudinal acoustic waves and the medium in a flow-chamber. The pump comprises a non-planar, transducer and an associated chamber for providing a controllable, focused, acoustic traveling wave therein. The chamber includes a tapered passage corresponding to the focused beam pattern of the focused acoustic traveling wave through which the liquid medium flows and/or cavitation is induced and/or controlled. The pump therefore utilizes a focused, non-planar, acoustical transducer responsive to frequency input for directing longitudinal acoustic waves into the flow-chamber which induces a pressure gradient. The medium in the flow-chamber flows in the direction of travel of the acoustic wave in the chamber as a result of acoustic streaming. The exit orifice of the nozzle in communication with the chamber is strategically located at about the focal zone of the focused, traveling wave.

Abstract: An ultrasonic pump in which a medium is pumped by the interaction between longitudinal acoustic waves and the medium in a flow-chamber. The pump comprises a transducer and an associated chamber for providing a controllable, focused, acoustic traveling wave therein. The chamber includes a tapered passage corresponding to the focused beam pattern of the focused acoustic traveling wave through which the liquid medium flows and/or cavitation is induced and/or controlled. The pump therefore utilizes an acoustical transducer responsive to frequency input for directing longitudinal acoustic waves into the flow-chamber which induces a pressure gradient. The medium in the flow-chamber flows in the direction of travel of the acoustic wave in the chamber as a result of acoustic streaming. The exit orifice of the nozzle in communication with the chamber is strategically located at about the focal zone of the focused, traveling wave.

Abstract: The ejection orifice (7) of a micropump including a baseplate (3) of glass and a cover plate (4) of silicon and intended for ejecting small liquid drops, has a diameter of about 50 &mgr;m, and is located in the center of a flat front surface (12) which, in order to avoid accumulations of liquid in the region of the ejection orifice (7), is only 8 times the area thereof and, along a continuous circular edge, is adjacent a lateral surface (13) in the form of an envelope of truncated cone. The front surface (12) and the lateral surface (13) have a surface roughness of not more than N4 and are provided, for example, with a hydrophobic plasma polymer coating.

Abstract: A pump having a main pump body including a casing to which a fluid is supplied, and a pump section, an input valve section, and an output valve section which are provided opposingly to one surface in the casing. Each of the pump section, the input valve section, and the output valve section has an actuator section. The input valve section, the pump section, and the output valve section are provided opposingly to the back surface of the casing for selectively forming a flow passage on the back surface of the casing in accordance with selective displacement action of the input valve section, the pump section, and the output valve section in a direction approaching or separating from the back surface of the casing. The fluid is controlled for its flow in accordance with the selective formation of the flow passage.

Abstract: In a device for ejecting small amounts of a liquid material having accurately defined volumes from a chamber (1), the chamber has a nozzle aperture (7) and a rod (9) is mounted in or attached to a wall of the chamber (1), so that an end surface (11) of the rod is located opposite and at a small distance of the nozzle aperture (7). A driving device is coupled to the rod (9) for displacing the end surface (11) forwards and backwards inside the chamber with a very small stroke, with a high acceleration and a large force, so that a pressure wave is formed and propagates in the material in the chamber (1). The pressure wave then ejects material out of the nozzle aperture (7).

Abstract: A pump having a main pump body including a casing to which a fluid is supplied, and a pump section, an input valve section, and an output valve section which are provided opposingly to one surface in the casing. Each of the pump section, the input valve section, and the output valve section has an actuator section. The input valve section, the pump section, and the output valve section are provided opposingly to the back surface of the casing for selectively forming a flow passage on the back surface of the casing in accordance with selective displacement action of the input valve section, the pump section, and the output valve section in a direction approaching or separating from the back surface of the casing. The fluid is controlled for its flow in accordance with the selective formation of the flow passage.

Abstract: A compact pump has a pump chamber, inlet and outlet channels communicating with the pump chamber, and a pair of check valve units between the pump chamber and the inlet and outlet channels. Each check valve unit has a thin film check valve membrane, and a check valve body with a channel opened and closed by the check valve membrane due to a pressure difference.

Abstract: A flow controller for use in microelectromechanical systems. The principal components of the controlled are a microvalve and sensor which are micromachined on one surface of a substrate that is formed with a fluid flow channel. The microvalve includes a shape memory alloy actuator element that is operated by a feedback signal from a control circuit. The sensor can be a fluid flow rate sensor or a fluid temperature sensor or a fluid pressure sensor. Conditions in the channel are sensed for generating the feedback signal.

Abstract: A method of controlling fluid flow in a channel in a microfluidic flow control device by introducing fluid to the channel, with the fluid flowing in a flow direction and controllably deforming material defining the channel in a direction perpendicular to the flow direction to control fluid flow in the channel. The channel is formed between a first plate and a second plate and controllably deforming material defining the channel comprises deforming at least one of the first and second plates. Material defining the channel extends continuously between an inlet port and an outlet port. Controllably deforming material defining the channel preferably comprises deforming the first plate into contact with a seat formed in the second plate to close the channel. The seat may be formed by a ridge having a smoothly changing profile in section across the channel. The method may be operated to generate a pumping, filtering, trapping or mixing function. Apparatus for carrying out the method is also disclosed.

Abstract: A device for discharging a liquid raw material(fuel) is provided, including a structure for discharging liquid having at least a pressurizing means for discharging liquid, a pressure chamber, a flow path communicating with the pressure chamber, and an air bubble trap cell communicating with the pressure chamber via the flow path. According to this device, a trapped air bubble can be securely released.

Abstract: A micro pump member, in which a plurality of cells formed in a base part is used as pressurizing chambers, and side walls forming said pressurizing chambers are constructed by piezoelectric/electrostrictive elements, and the volume of said pressurizing chambers is changed by the displacement of said piezoelectric/electrostrictive elements to produce a pressure in the pressurizing chambers. Said pressurizing chambers are formed to be independent of the adjacent pressurizing chambers. Activation can be carried out by applying a driving electric field having a high field strength to the pressuring chambers, so that a greater displacement and a higher response can be obtained with a smaller field strength.

Abstract: A micro pump having at least one pump member for conveying a fluid by action of pressure is provided; the pump member comprising a pump unit, and the pump unit being formed by at least one actuator member for generating a pressure fluctuation and a fluid channel member in which a fluid flows, and the actuator member provided with a cell formed by disposing two side walls made of piezoelectric/electrostrictive elements or antiferrodielectric elements on a connecting plate, and covering surface facing the connecting plate between said side walls with a cover plate; and the actuator member selectively forms a fluid channel and generates pressure fluctuation in the fluid channel member due to displacement of the cell caused by expansion/contraction of the side wall: present micro pump being small and thin in size, with attainment of increasing fluid ejection amount(move amount), and high speed in response.

Abstract: An electrostrictive micro-pump is provided for controlling a fluid flow through a cannula or other narrow liquid conduit. The micro-pump includes a pump body having a passageway for conducting a flow of fluid, a pump element formed from a piece of viscoelastic material and disposed in the passageway, and a control assembly coupled to the viscoelastic material for electrostatically inducing a peristaltic wave along the longitudinal axis of the pump element to displace fluid disposed within the pump body. The control assembly includes a pair of electrodes disposed over upper and lower sides of the pump element. The lower electrode is formed from a plurality of uniformly spaced conductive panels, while the upper electrode is a single sheet of conductive material. A switching circuit is provided for actuating the conductive panels of the lower electrode in serial, multiplex fashion to induce a peristaltic pumping action.

Abstract: A valve for use in laminated plastic microfluidic structures. The valve comprises first, second, and third layers of flexible material separated by first and second spacing layers to form microfluidic channels, and having an actuator section to selectively isolate the microfluidic channels from each other. The structure can also be used as a recirculating pump.

Abstract: A peristaltic pump with three coaxial cylindrical components; a high-modulus rod contained within a piezoelectric tube, which in turn is contained within a cylindrical pressure casing, which may the casing of a hydraulic cylinder. The casing is filled with ERF. The piezoelectric tube has a plurality of electrode bands attached to its outer surface and is coated on its interior with an electrically conductive material. The electrodes are voltage-activated to cause certain portions of the tube to expand and others to contract, resulting in peristaltic action. The applied voltage also causes the ERF to form a gel state both inside and outside of the piezoelectric tube.

Abstract: An electrostrictive micro-pump is provided for controlling a fluid flow through a cannula or other narrow liquid conduit. The micro-pump includes a pump body having a passageway for conducting a flow of fluid, a pump element formed from a piece of viscoelastic material and disposed in the passageway, and a control assembly coupled to the viscoelastic material for electrostatically inducing a peristaltic wave along the longitudinal axis of the pump element to displace fluid disposed within the pump body. The control assembly includes a pair of electrodes disposed over upper and lower sides of the pump element. The lower electrode is formed from a plurality of uniformly spaced conductive panels, while the upper electrode is a single sheet of conductive material. A switching circuit is provided for actuating the conductive panels of the lower electrode in serial, multiplex fashion to induce a peristaltic pumping action.

Abstract: A suspended p-GaN membrane is formed using photochemical etching which membrane can then be used in a variety of MEMS devices. In the illustrated embodiment a pump is comprised of the p-GaN membrane suspended between two opposing, parallel n-GaN support pillars, which are anchored to a rigid substrate below the pillars. The p-GaN membrane bows upward between the pillars in order to relieve stress built up during the epitaxial growth of membrane. This bowing substantially increases the volume of the enclosed micro-channel defined between membrane and substrate below. The ends of membrane are finished off by a gradual transition to the flat underlying n-GaN layer in which fluidic channels may also be defined to provide inlet and outlet channels to microchannel. A traveling wave or sequential voltage applied to the electrodes causes the membrane to deform and provide a peristaltic pumping action in the microchannel.

Abstract: A positive displacement pump is composed of a first actuator for moving a piston and a housing relatively, a cylinder for accommodating the piston, and a second actuator for moving the cylinder and the housing relatively.

Abstract: The micro pump 100 comprises a first flow pass 115 for changing the flow pass resistance in accordance with the differential pressure, a second flow pass 117 wherein the percentage change in flow pass resistance relative to the differential pressure is less than that of the first flow pass 115, pressure chamber 109 connected to the first flow pass 115 and the second flow pass 117, and a piezoelectric element 107 for changing the pressure within the pressure chamber 109 so as to transport minute amounts of fluid with high precision using a simple construction. The ratio of the flow pass resistance of the first flow pass 115 and the flow pass resistance of the second flow pass 117 differs by changing the pressure within the pressure chamber 109 via the piezoelectric element 107, such that fluid can be transported in a standard direction and an opposite direction.

Abstract: The invention concerns a process for specific and direct manipulation of small quantities of matter on solid-body surfaces, in which surface waves are generated with at least one surface-wave generator and the impulse of one or more surface waves is made to interact with at least one quantity of matter, in order to cause a movement in a desired direction. The invention also concerns a device for implementing the process according to the invention.

Abstract: The fluid discharge device includes an axial drive device for giving an axial relative displacement to between a piston and a cylinder, a device for giving rotary motion, and a device for pressure feed of fluid. The ON/OFF control of discharge flow rate can be fulfilled by changing the fluid resistance of the discharge passage with the axial drive device.

Abstract: A piezoelectric micropump is disclosed for pumping fluid from a container to a delivery point in low volumes and at controlled flow rates. The pumping action is created by movement of two or three diaphragms. The movement of each diaphragm is caused by expansion and contraction of an attached piezoelectric actuator. Coordination of the movement of the diaphragms creates unidirectional flow of the fluid. The piezoelectric actuators are cantilevered between the pump body and the diaphragms to provide greater deflection of the diaphragms. The piezoelectric actuators preferably are piezoelectric bimorphs such that the diaphragms can function as both seals and pumps.

Abstract: An actively controlled flexural plate wave device provides a micro-scale pump. A method of actively controlling a flexural plate wave device produces traveling waves in the device by coordinating the interaction of a magnetic field with actively controlled currents. An actively-controlled flexural plate wave device can be placed in a fluid channel and adapted for use as a micro-scale fluid pump to cool or drive micro-scale systems, for example, micro-chips, micro-electrical-mechanical devices, micro-fluid circuits, or micro-scale chemical analysis devices.

Abstract: A mini-environment control device includes an individual enclosure to contain a sample and to isolate it from the external environment. An array of micropumps attached to the individual enclosure generates and maintains a controlled vacuum in the individual enclosure. Transfer means introduce the sample into the individual enclosure and extract it therefrom. The micropumps of the array of micropumps can be of a type employing the thermal transpiration effect. Temperature and pressure microsensors and a gas analyzer enable the operation of the array of micropumps to be controlled by an onboard microcomputer. The atmosphere surrounding a sample is therefore controlled.

Abstract: A printhead for an inkjet printer employs an integral pump disposed in an ink feed channel, input well, or output well to circulate ink to the ink expulsion chambers in the printhead.

Abstract: The fluidic drive for miniature acoustic-fluidic pump and mixer is comprised of an acoustic transducer attached to an exterior or interior of a fluidic circuit or reservoir. The transducer converts radio frequency electrical energy into an ultrasonic acoustic wave in a fluid that in turn generates directed fluid motion through the effect of acoustic streaming. Acoustic streaming results due to the absorption of the acoustic energy in the fluid itself. This absorption results in a radiation pressure and acoustic streaming in the direction of propagation of the acoustic propagation or what is termed “quartz wind”.

Abstract: A displacement pump with a pump housing containing a pump chamber of varying volume, the limiting walls of which includes a moveable portion or diaphragm, the movement and/or deformation of which varies the pump chamber volume. The pump chamber has a fluid inlet on the suction side of the pump and a fluid outlet on the pressure side. Both the fluid inlet and the fluid outlet, or possibly only one of them, includes a flow controlling element having one diffuser and one diffuser inlet which, for the same flow, has a larger pressure drop in one flow direction (the nozzle direction) than in the opposite flow direction (the diffuser direction). A drive element is coupled to the diaphragm, whereby the diaphragm can be caused to oscillate, so that the fluid volume in the pump chamber is caused to pulsate and thereby produce a net flow of fluid through the pump.

Abstract: A microejector pump for generating microdrops includes at least one pump chamber configured in a silicon chip and a piezoelectrically actuable silicon membrane arranged over the pump chamber. The pump chamber is connected to at least one supply line as well as a discharge line provided with an ejection orifice. A glass chip closes off at least the pump chamber from the silicon membrane. The microejector pump can also include an integral heater and controller.

Abstract: A diaphragm pump, which is preferably electrostatically actuated, but which may be activated by other forces such as electromagnetic or piezoelectric actuation. The pump is formed by a pump body having a pump chamber formed therein. First and second diaphragms each having a set of valve holes in the diaphragm surface thereof are mounted in the chamber. Also provided are at least one inlet and at least one outlet port for communication with the pump chamber. The ports are positioned for sealing contact with the diaphragms at points that are not aligned with the holes in the diaphragms. A driver electrostatically actuates the diaphragms to cause diaphragm movement to a plurality of diaphragm positions to control flow of fluid through the pump. The first position is when the diaphragms are spaced from one another and from the ports to permit flow of fluid through the pump chamber.

Abstract: A compact active vapor compression cycle heat transfer device. The device of the invention includes a flexible diaphragm serving as the compressive member in a layered compressor. The compressor is stimulated by capacitive electrical action and drives the relatively small refrigerant charge for the device through a closed loop defined by the compressor, an evaporator and a condenser. The evaporator and condenser include microchannel heat exchange elements to respectively draw heat from an atmosphere on a cool side of the device and expel heat into an atmosphere on a hot side of the device. The overall structure and size of the device is similar to microelectronic packages, and it may be combined to operate with similar devices in useful arrays.

Abstract: A fuel injection system is provided with an interior pumping chamber (94) which is connected to a fuel inlet (98). A pumping element (90) is provided with piezoelectric elements (124) which are interspaced between electrodes (126, 128). The pumping element (90) is electrically connected to an ECU (58). Activation of the piezoelectric elements causes pumping element (90) to expand and thereby impart pressure from a pressure surface (112) which extends into the pumping chamber (94). Fuel in the pressure chamber, as a result of the piezoelectric elements is pushed from the pressure chamber and through an injection valve (116).The applicants are reminded that formal drawings are now required. Further, as noted in the Office Action of Dec. 16, 1999, in FIG. 2, numeral 124 should be changed to indicate mounting plate 121. On drawing sheet 6, FIG. 6a and FIG. 6b should be indicated.

Abstract: A microactuated device and method of making the same in which an electromagnetic driver, overlapping a magnetically permeable diaphragm, is utilized to drive the microactuated device. Through the use of an electromagnetic driver to provide the motive force for a microactuated device, exceptional performance may be realized, e.g., with a substantially reduced drive voltage for micropumps, microvalves, and the like, and with stronger and more precise sensory outputs for microactuated sensors and the like. Moreover, by overlapping the electromagnetic driver over a diaphragm, a number of batch processing techniques, each of which is well suited for mass production, may be used in the fabrication of extremely compact and cost effective integrated devices.

Abstract: A mesopump having a plurality of elementary cells. The cells each have a body forming a cavity having an electrode on one curved surface and a second surface facing the electrode. Electrical connections selectively energize the electrode. A diaphragm is mounted under tensile load with its major portion located in the cavity so that the diaphragm deflects toward the electrode surfaces upon application of voltage to the electrode and returns to its original position when voltage is stopped. A lateral conduit is located at at least one end of the body for fluid communication with the cavity. The lateral conduits are operably connected to a portion of the diaphragm mounted in the body and are opened and closed by movement of the diaphragm. A vertical conduit on at least one curved surface controls flow of fluid by movement of the diaphragm into and out of contact with the vertical conduit.

Abstract: A magnetotrictive peristaltic pump transfers a fluid from a supply chamber o a receiving chamber. The pump has a housing and a core section mounted within the housing. The core section is fabricated from a magnetostrictive material such as Terfenol-D, which can be made to expand directionally in the presence of a magnetic field. There is a fluid tight seal between the inner surface of the housing and the outer surface of the core section. Wrapped around the outer surface of the housing are a plurality of electrical coils. The positive terminal and the negative terminal of each coil are connected to a signal generator which generates direct current electrical signals to sequentially energize each coil. Energizing any one of the coils creates a magnetic field in the general area of the coil. In the presence of this magnetic field, the core section expands longitudinally resulting in lateral/radial shrinkage of the core section which creates a cavity in the general area of the magnetic field.

Abstract: A peristaltic piezoelectrically actuated fluid pump including two or more pairs of piezoelectric deformable members that are self-actuated, a flexible hose member, a pump chamber, inlet and outlet ports for communicating the pump chamber with the exterior of the flexible hose member, valves for opening and closing the ports, and a power supply is provided. The diaphragm members may include a prestressed piezoelectric element which is durable, inexpensive and lightweight as compared with diaphragm members of prior diaphragm pumps of comparable discharge capacity, and is actuated via electrical signals from an outside power source. Each pair of piezoelectric diaphragm members is actuated out of phase with the other(s) so as to allow fluid to be pumped through the flexible hose member peristaltically.

Abstract: A piezoelectrically actuated fluid pump including a pump housing, a pump chamber, inlet and outlet ports for communicating the pump chamber with the exterior of the pump housing, valves for opening and closing the ports, a pre-stressed piezoelectric diaphragm member which is self-actuated, a piston member, and a power source is provided. The diaphragm member includes a prestressed piezoelectric element which is durable, inexpensive and lightweight as compared with diaphragm members of prior diaphragm pumps of comparable discharge capacity, and is actuated via electrical signals from an outside power source. The diaphragm member drives the piston member. No exterior mechanisms are necessary for driving the diaphragm member.

Abstract: A ferroelectric pump has one or more variable volume pumping chambers internal to a housing. Each chamber has at least one wall comprising a dome shaped internally prestressed ferroelectric actuator having a curvature and a dome height that varies with an electric voltage applied between an inside and outside surface of the actuator. A pumped medium flows into and out of each pumping chamber in response to displacement of the ferroelectric actuator. The ferroelectric actuator is mounted within each wall and isolates each ferroelectric actuator from the pumped medium, supplies a path for voltage to be applied to each ferroelectric actuator, and provides for positive containment of each ferroelectric actuator while allowing displacement of the entirety of each ferroelectric actuator in response to the applied voltage.

Abstract: A piezoelectrically actuated fluid pump including a pump housing, a pump chamber, inlet and outlet ports for communicating the pump chamber with the exterior of the pump housing, valving means for opening and closing the ports, two pre-stressed piezoelectric diaphragm members which are self-actuated, and energizing means is provided. The diaphragm members include a prestressed piezoelectric element which is durable, inexpensive and lightweight as compared with diaphragm members of prior diaphragm pumps of comparable discharge capacity, and is actuated via electrical signals from an outside power source. No exterior mechanical means for driving the diaphragm members is necessary. A modification is disclosed in which a central computer independently controls the phase angle of oscillation of the two diaphragm members, providing precise flow rate control.

Abstract: A micromembrane pump is described which is self-priming and self-filling. For this, the pump chamber (14) is so configured that in a drained condition of the pump chamber (14), the pump membrane (4) adjoins the pump chamber wall (22), which causes the volume of the pump chamber (14) to be minimized. For this, the pump chamber wall (22) can be flat, so that the pump membrane (4) adjoins the flat pump chamber wall (22) in its unshifted rest position. Preferably, the pump includes membrane valves which consist of a valve membrane (3) situated between two halves of the housing (1, 2), and valve seats (10, 16). It also includes a heteromorphic piezoactuator (5) attached to the pump membrane (4). The compact pump is suited to deliver gases and liquids, and can be manufactured in cost-effective fashion from only a few components.

Abstract: A printhead for an inkjet printer employs an integral pump disposed in an ink feed channel, input well, or output well to circulate ink to the ink expulsion chambers in the printhead.

Abstract: A micropump in which a fluid is pumped by the interaction of longitudinal acoustic waves and the fluid in the microchannel. The micropump having an acoustical transducer responsive to a high-frequency input and directing a longitudinal acoustic wave into the channel which induces a pressure gradient. The fluid in the channel flowing in the direction of travel of the acoustic wave in the channel.

Abstract: Micromachined pumps including a channel formed between a first membrane and a substrate or between first and second flexible membranes. A series of electrically conductive strips is applied to a surface of the substrate or one of the membranes. Application of a sequential voltage to the series of strips causes a region of closure to progress down the channel to achieve a pumping action.