Abstract: A heat exchanger and method of manufacturing thereof comprises an interface layer for cooling a heat source. The interface layer is coupled to the heat source and is configured to pass fluid therethrough. The heat exchanger further comprises a manifold layer that is coupled to the interface layer. The manifold layer includes at least one first port that is coupled to a first set of individualized holes which channel fluid through the first set. The manifold layer includes at least one second port coupled to a second set of individualized holes which channel fluid through the second set. The first set of holes and second set of holes are arranged to provide a minimized fluid path distance between the first and second ports to adequately cool the heat source. Preferably, each hole in the first set is positioned a closest optimal distance to an adjacent hole the second set.

Abstract: A miniaturized micromachined (MEMS) accelerometer-based sensor suitable for use in biological applications, such as a middle ear implant, is provided. An encapsulation layer is deposited on top of an accelerometer proof mass and flexure prior to release of the proof mass and flexure. The encapsulation layer protects the proof mass and flexure from subsequent processing steps, such as dicing and packaging, which enables fabrication of finished devices having reduced size. Surfaces within the accelerometer may be passivated after releasing the proof mass and flexure. Remote piezoresistive sensing is performed in order to provide low noise and reduced sensor head size.

Abstract: A liquid cooling system utilizing minimal size and volume enclosures, air pockets, compressible objects, and flexible objects is provided to protect against expansion of water-based solutions when frozen. In such a system, pipes, pumps, and heat exchangers are designed to prevent cracking of their enclosures and chambers. Also described are methods of preventing cracking in a liquid cooling system. In all these cases, the system must be designed to tolerate expansion when water is frozen.

Abstract: A method and apparatus for cooling a hat source configured along a lane. The heat exchanger comprises an interface layer that perform thermal exchanger with the heat source and configured to pass fluid from a first side to a second side. The manifold layer comprises a first layer in contact with the heat source and has an appropriate thermal conductivity to pass heat to the interface layer. The manifold layer further comprises a second layer couple to the first layer and in contact with the second side of the interface layer. The first layer comprises a recess area having a heat conducting region in contact with the heat exchanging layer. The first layer includes at least one inlet and/or outlet port. The second layer includes at least one inlet and/or outlet port. At least one inlet and/or outlet port is positioned substantially parallel or perpendicular with respect to the plane.

Abstract: A heat exchanger apparatus and method of manufacturing comprising: an interface layer for cooling a heat source and configured to pass fluid therethrough, the interface layer having an appropriate thermal conductivity and a manifold layer for providing fluid to the interface layer, wherein the manifold layer is configured to achieve temperature uniformity in the heat source preferably by cooling interface hot spot regions. A plurality of fluid ports are configured to the heat exchanger such as an inlet port and outlet port, whereby the fluid ports are configured vertically and horizontally. The manifold layer circulates fluid to a predetermined interface hot spot region in the interface layer, wherein the interface hot spot region is associated with the hot spot. The heat exchanger preferably includes an intermediate layer positioned between the interface and manifold layers and optimally channels fluid to the interface hot spot region.

Abstract: A microchannel heat exchanger coupled to a heat source and configured for cooling the heat source comprising a first set of fingers for providing fluid at a first temperature to a heat exchange region, wherein fluid in the heat exchange region flows toward a second set of fingers and exits the heat exchanger at a second temperature, wherein each finger is spaced apart from an adjacent finger by an appropriate dimension to minimize pressure drop in the heat exchanger and arranged in parallel. The microchannel heat exchanger includes an interface layer having the heat exchange region. Preferably, a manifold layer includes the first set of fingers and the second set of fingers configured within to cool hot spots in the heat source. Alternatively, the interface layer includes the first set and second set of fingers configured along the heat exchange region.

Abstract: An electroosmotic pump and method of manufacturing thereof. The pump having a porous structure adapted to pump fluid therethrough, the porous structure comprising a first side and a second side, the porous structure having a plurality of fluid channels therethrough, the first side having a first continuous layer of electrically conductive porous material deposited thereon and the second side having a second continuous layer of electrically conductive porous material deposited thereon, the first second layers coupled to a power source, wherein the power source supplies a voltage differential between the first layer and the second layer to drive fluid through the porous structure at a desired flow rate. The continuous layer of electrically conductive porous material is preferably a thin film electrode, although a multi-layered electrode, screen mesh electrode and beaded electrode are alternatively contemplated.

Abstract: A method of forming an adhesive force includes removing a seta from a living specimen, attaching the seta to a substrate, and applying the seta to a surface so as to establish an adhesive force between the substrate and the surface. The seta is applied to the surface with a force perpendicular to the surface. The seta is then pulled with a force parallel to the surface so as to preload the adhesive force of the seta.

Abstract: Apparatus and methods according to the present invention preferably utilize electroosmotic pumps that are capable of generating high pressure and flow without moving mechanical parts and the associated generation of unacceptable electrical and acoustic noise, as well as the associated reduction in reliability. These electroosmotic pumps are preferably fabricated with materials and structures that improve performance, efficiency, and reduce weight and manufacturing cost relative to presently available micropumps. These electroosmotic pumps also preferably allow for recapture of evolved gases and deposited materials, which may provide for long-term closed-loop operation. Apparatus and methods according to the present invention also allow active regulation of the temperature of the device through electrical control of the flow through the pump and can utilize multiple cooling loops to allow independent regulation of the special and temporal characteristics of the device temperature profiles.

Abstract: A method of forming an adhesive force includes removing a seta from a living specimen, attaching the seta to a substrate, and applying the seta to a surface so as to establish an adhesive force between the substrate and the surface. The seta is applied to the surface with a force perpendicular to the surface. The seta is then pulled with a force parallel to the surface so as to preload the adhesive force of the seta.

Abstract: Apparatus and methods according to the present invention preferably utilize electroosmotic pumps that are capable of generating high pressure and flow without moving mechanical parts and the associated generation of unacceptable electrical and acoustic noise, as well as the associated reduction in reliability. These electroosmotic pumps are preferably fabricated with materials and structures that improve performance, efficiency, and reduce weight and manufacturing cost relative to presently available micropumps. These electroosmotic pumps also preferably allow for recapture of evolved gases and deposited materials, which may provide for long-term closed-loop operation. Apparatus and methods according to the present invention also allow active regulation of the temperature of the device through electrical control of the flow through the pump and can utilize multiple cooling loops to allow independent regulation of the special and temporal characteristics of the device temperature profiles.

Abstract: Apparatus and methods according to the present invention preferably utilize electroosmotic pumps that are capable of generating high pressure and flow without moving mechanical parts and the associated generation of unacceptable electrical and acoustic noise, as well as the associated reduction in reliability. These electroosmotic pumps are preferably fabricated with materials and structures that improve performance, efficiency, and reduce weight and manufacturing cost relative to presently available micropumps. These electroosmotic pumps also preferably allow for recapture of evolved gases and deposited materials, which may provide for long-term closed-loop operation. Apparatus and methods according to the present invention also allow active regulation of the temperature of the device through electrical control of the flow through the pump and can utilize multiple cooling loops to allow independent regulation of the special and temporal characteristics of the device temperature profiles.

Abstract: An apparatus using a resonator probe for determining an electronic property of a conductor across a dielectric. The apparatus has a device for inducing lateral mechanical oscillations of the resonator probe and a voltage source for producing a voltage difference between the resonator probe and the conductor to create an electronic drag between the conductor and resonator probe, thus damping the mechanical oscillations of the probe. The electronic property, such as charge carrier mobility, surface resistance, charge carrier lifetime and the number of charge carriers is determined from the damping experienced by the probe.

Abstract: A micromachined accelerometer for measuring acceleration in a direction parallel with the plane of the accelerometer substrate. The accelerometer has a strain-isolation pedestal, a flexure attached to the pedestal, and a proof mass attached to the flexure. The pedestal is wider than the flexure and does not bend when the device is under acceleration. The pedestal serves to isolate the flexure from substrate strain which may be caused by device packaging or temperature variations. Preferably, the joint between the pedestal and flexure, and the joint between the flexure and proof mass are smoothed to prevent stress concentration. The joints have a radius of curvature of at least 1 micron. A piezoresistor is located in one sidewall of the flexure. Alternatively, two piezoresistors are located on the flexure, with one on each sidewall. In this embodiment, a center-tap connection is provided to the point where the two piezoresistors are connected.

Abstract: A method of forming electrical elements on the sidewalls of deformable micromechanical structures such as flexible, high aspect ratio beams. The micromechanical structure is made of a semiconductor material such as silicon. The method includes angled ion implantation at an angle nonnormal to the substrate surface. The angle ensures that ions are implanted into appropriately oriented sidewalls. Multiple ion implantations can be performed to form electrical elements into different sidewalls. Masking techniques can be used to restrict the locations where ions are implanted. Alternatively, several different types of ion diffusion can be used to expose the sidewall in selected regions. The present invention can form conductive pathways which are continuous between perpendicular surfaces. This enables electrical elements on vertical surfaces to communicate with electronics on horizontal surfaces, for example. The dopant ion concentration and ion species can be controlled to form many different electrical elements.

Abstract: A micromachined structure providing for independent vertical and lateral deflection sensing. The structure uses high aspect ratio ribs which bend much more easily in one direction than in other directions (i.e., have a predominant direction of compliance). One or more ribs are combined to form beams which also have one predominant direction of compliance. Two such beams are bonded end to end, and one end of the beam pair is bonded to a base. The beams are oriented orthogonally to one another such that they independently bend to vertical and lateral external forces. Further, three dimensional force sensing can be accomplished by adding a third beam. Sensors can independently sense the bending in each beam and thereby independently measure the dimensional components of bending forces applied to the free end of the structure. In the preferred embodiment, piezoresistive sensors are formed on the ribs comprising the beams. The piezoresistors can be made by ion-implantation, for example.

Abstract: The use of a dual element approach provides high resolution position sensors based on electron tunneling. This approach allows miniaturization while utilizing the position sensitivity of electron tunneling to give high resolution. The dual-element tunneling structure overcomes the narrow bandwidth limitations of a single-element structure. A sensor with an operating range of 5 Hz to 10 kHz, which can have applications as an acoustic sensor, is disclosed. Noise is analyzed for fundamental thermal vibration of the suspended masses and is compared to electronic noise. It is shown that miniature tunnel accelerometers can achieve resolution such that thermal noise in the suspended masses is the dominant cause of the resolution limit. With a proof mass of order 100 mg, noise analysis predicts limiting resolutions approaching 10.sup.-9 g/.sqroot.Hz in a 300 Hz band and 10.sup.-8 g/.sqroot.Hz at 1 kHz.

Abstract: Methods and apparatus for measuring gravitational and inertial forces, magnetic fields, or wave or radiant energy acting on an object or fluid in space provide an electric tunneling current through a gap between an electrode and that object or fluid in space and vary that gap with any selected one of such forces, magnetic fields, or wave or radiant energy acting on that object or fluid. These methods and apparatus sense a corresponding variation in an electric property of that gap and determine the latter force, magnetic fields, or wave or radiant energy in response to that corresponding variation, and thereby sense or measure such parameters as acceleration, position, particle mass, velocity, magnetic field strength, presence or direction, or wave or radiant energy intensity, presence or direction.

Abstract: An uncooled infrared tunneling sensor in which the only moving part is a diaphragm which is deflected into contact with a micromachined silicon tip electrode prepared by a novel lithographic process. Similarly prepared deflection electrodes employ electrostatic force to control the deflection of a silicon nitride, flat diaphragm membrane. The diaphragm exhibits a high resonant frequency which reduces the sensor's sensitivity to vibration. A high bandwidth feedback circuit controls the tunneling current by adjusting the deflection voltage to maintain a constant deflection of the membrane. The resulting infrared sensor can be miniaturized to pixel dimensions smaller than 100 .mu.m. An alternative embodiment is implemented using a corrugated membrane to permit large deflection without complicated clamping and high deflection voltages.

Abstract: An uncoated interdigitated transducer is cooled from a temperature above the dew point to a temperature below the dew point, while a parameter of a signal of the transducer is measured. The reduction in temperature causes a monotonic change in transducer signal because that signal is sensitive primarily to the water loading of the transducer surface as water forms on that surface due to the reduction in temperature. As the dew point is approached with temperature reduction, the slope of the curve of transducer signal with respect to temperature, remains relatively constant. However, as the dew point is reached the slope of that curve increases and because of changes in the structure of the water layer on the surface of the transducer, at the dew point the transducer responds with a clear shift in the rate at which the transducer signal changes. The temperature at which the second derivative of signal vs. temperature peaks can be readily used to identify with extreme accuracy, the precise dew point.