Abstract: A rugged microsensor assembly is disclosed that measures both the velocity and angular direction of an incoming air stream. The microsensor assembly includes at least two flow sensors, each orientated to measure a different velocity component of the incoming air stream. The velocity components are related by the geometry between the sensors, and the angular direction and velocity of the incoming air stream are determined by examining the measured velocity components. The preferred sensor is a fully passivated thermal differential microanemometer with back contacts, designed to operate in harsh environments.

Abstract: A microcathode which integrates both an electron emitter, or cathode, and an extractor electrode. The electron emitter is attached to the back side of a thin film microstructure on a first surface of a substrate. Electrons are emitted from the electron emitter and into a via extending through the substrate. An electron beam is formed which is pulled through the via and out of the microcathode by an extractor electrode on a second surface of the substrate. The extractor electrode modulates the electron beam current, defines the beam profile, and accelerates the electrons toward an anode located outside of the microcathode. Microcathode of this invention are particularly suitable as electron emitting devices useful for various types of electron beam utilizing equipment such as flat cathode ray tube displays, microelectronic vacuum tube amplifiers, electron beam exposure devices and the like.

Abstract: A carbon monoxide sensor and method is shown and described. The sensor includes a sensing element that includes an adsorbent dispersed over a support material. The adsorbent is capable of exothermically adsorbing carbon monoxide. The sensor also includes a temperature sensor in contact with the sensing element and a signal processing module coupled to the temperature sensor. The temperature sensor communicates signals indicative of a temperature increase of the sensing element to the processing module, thereby indicating an adsorption and, therefore, a presence of carbon monoxide.

Abstract: An engine and associated methods are disclosed. An engine in accordance with the present invention comprises a housing defining a cavity and a slidable member disposed in the cavity. The slidable member is preferably configured to form one or more combustion chambers, and the slidable member adapted to slide back and fourth relative to the housing in a cycle. One or more intake ports are provided for selectively providing fuel to the one or more combustion chambers during selected timed during the cycle. One or more exhaust ports are provided for selectively venting exhaust from the one or more combustion chambers during selected times during the cycle. The intake and exhaust ports are preferably disposed so that intake and exhaust flows are in the same direction (e.g. uniflow).

Abstract: A microcathode which integrates both an electron emitter, or cathode, and an extractor electrode. The electron emitter is attached to the back side of a thin film microstructure on a first surface of a substrate. Electrons are emitted from the electron emitter and into a via extending through the substrate. An electron beam is formed which is pulled through the via and out of the microcathode by an extractor electrode on a second surface of the substrate. The extractor electrode modulates the electron beam current, defines the beam profile, and accelerates the electrons toward an anode located outside of the microcathode. Microcathode of this invention are particularly suitable as electron emitting devices useful for various types of electron beam utilizing equipment such as flat cathode ray tube displays, microelectronic vacuum tube amplifiers, electron beam exposure devices and the like.

Abstract: An engine and associated methods are disclosed. An engine in accordance with the present invention comprises a housing defining a cavity and a slidable member disposed in the cavity. The slidable member is preferably configured to form one or more combustion chambers, and the slidable member adapted to slide back and fourth relative to the housing in a cycle. One or more intake ports are provided for selectively providing fuel to the one or more combustion chambers during selected timed during the cycle. One or more exhaust ports are provided for selectively venting exhaust from the one or more combustion chambers during selected times during the cycle. The intake and exhaust ports are preferably disposed so that intake and exhaust flows are in the same direction (e.g. uniflow).

Abstract: A liquid flow microsensor having a flow tube with a sensor aperture on the surface and having a straight-through conduit for fluid flow. A sensor assembly is mounted within the sensor aperture, and includes a thermal sensor positioned to be within the straight-through conduit in direct communication with the fluid flow so as to sense thermal characteristics representative of a fluid flow rate.

Abstract: A knocking-based, micro-combustion engine constructed in three layers of micromachined material. Two outer layers contain means for directing gases and fuels into and out of vents in a middle layer. The middle layer has machined in it two, linear, free pistons with or without integral air springs, and vents for directing gases and fuels into and out of a combustion chamber. A high compression ratio is achieved. The engine can be constructed with means to generate electrical energy.

Abstract: A concentrator and sensor assembly are disclosed that use phased heaters to multiply the concentration levels that can be eluted, relative to operation with a single interactive element having a sorbent material to increase the concentration of desired gas constituents at a detector. This is accomplished here by providing two or more interactive concentrator elements that are selectively heated in a time phased sequence so that each of the interactive elements becomes heated and desorbs gas constituents into the sample fluid stream at substantially the same time that an upstream concentration pulse, produced by heating one or more upstream interactive elements, reaches the interactive element. This produces a multiplication effect that significantly increases the concentration of the gas constituents at the detector, thereby increasing the effective sensitivity of the detector.

Abstract: A fluid driving system for portable flow cytometers or other portable devices that accepts a less precise and less stable pressure source, and then adjusts the pressure in a closed-loop manner to maintain a constant, desired flow velocity. The fluid driving system may be used in portable or wearable cytometers for use in remote locations, such as at home or in the field.

Abstract: A misfire monitor for detecting cylinder misfires in an internal combustion engine. The monitor has a light detector that senses infrared light signals emerging from combustion gases through a window inserted on an exhaust pipe or manifold. Characteristics of a detected light signal indicate whether there is a firing or a misfire in any cylinder. Other information about the engine is deduced with processing of the detected signals and misfire counts. The detection is real time and functions well at all normal engine speeds and operating conditions.

Abstract: A microsensor housing having a structure with at least one inlet at one end and a thermal property sensor at the other end. Situated between the inlet and the sensor is a convection shield. Sampled fluid is taken in the inlet from a channel carrying the fluid to be sampled. The convection flow lines of the fluid are barred by the convection shield. The fluid is diffused into a cavity between the shield and sensor. The sensor detects a thermal property of the diffused fluid. One preferred shield has holes about its perimeter with a solid center part of the shield covering at a distance the sensor. The channel carrying the fluid may have screens to reduce turbulence noise and to aid in fluid transport to and from the sensor housing.

Abstract: A microsensor housing having a structure with at least one inlet at one end and a thermal property sensor at the other end. Situated between the inlet and the sensor is a convection shield. Sampled fluid is taken in the inlet from a channel carrying the fluid to be sampled. The convection flow lines of the fluid are barred by the convection shield. The fluid is diffused into a cavity between the shield and sensor. The sensor detects a thermal property of the diffused fluid. One preferred shield has holes about its perimeter with a solid center part of the shield covering at a distance the sensor. The channel carrying the fluid may have screens to reduce turbulence noise and to aid in fluid transport to and from the sensor housing.

Abstract: An apparatus to normalize a flow rate of a fluid in a main flow channel is provided. The apparatus uses a moveable member, such as a flexible membrane disposed for reciprocating displacement, to produce a constant dither flow of the fluid that is independent of fluid composition. This dither flow generates a signal output from a normalizing flow sensor that both represents a characteristic property of the fluid and a flow rate calibration factor. A similar apparatus to determine the characteristic property or flow rate calibration factor is also provided. The devices disclosed may be used in numerous industrial, process, and medical flow system applications for normalization of flow sensors and to derive other properties of a fluid.

Abstract: A fiber optic endoscope which uses a bundle of coherent fiber to convey both an optical image in one direction and illumination light in the other direction. A fraction of the optical fibers are used for the illumination, and others of the fibers are used for the image. Notched fibers can be used for the illumination.

Abstract: A knocking-based, micro-combustion engine constructed in three layers of micromachined material. Two outer layers contain means for directing gases and fuels into and out of vents in a middle layer. The middle layer has machined in it two, linear, free pistons with or without integral air springs, and vents for directing gases and fuels into and out of a combustion chamber. A high compression ratio is achieved. The engine can be constructed with means to generate electrical energy.

Abstract: An apparatus to normalize a flow rate of a fluid in a main flow channel is provided. The apparatus uses a moveable member, such as a flexible membrane disposed for reciprocating displacement, to produce a constant dither flow of the fluid that is independent of fluid composition. This dither flow generates a signal output from a normalizing flow sensor that both represents a characteristic property of the fluid and a flow rate calibration factor. A similar apparatus to determine the characteristic property or flow rate calibration factor is also provided. The devices disclosed may be used in numerous industrial, process, and medical flow system applications for normalization of flow sensors and to derive other properties of a fluid.

Abstract: A knocking-based, micro-combustion engine constructed in three layers of micromachined material. Two outer layers contain means for directing gases and fuels into and out of vents in a middle layer. The middle layer has machined in it two, linear, free pistons with or without integral air springs, and vents for directing gases and fuels into and out of a combustion chamber. A high compression ratio is achieved. The engine can be constructed with means to generate electrical energy.

Abstract: A gasoline vapor recovery system wherein, during winter conditions, the volume of air/fuel vapor delivered to the storage tank is less than the volume of liquid gasoline removed from the tank but expands upon saturation within the storage tank to be approximately the same volume as the liquid gasoline removed. The volume of vapor to be delivered to the storage tank is based on pressure differential between the fuel vapor saturation pressure at a measured temperature at the storage tank and on the fuel vapor pressure of the air/fuel fluid delivered to the storage tank. During summer conditions, the volume of the air/fuel vapor delivered to the storage tank is controlled to be equal to the volume of liquid gasoline removed from the storage tank by drawing excess air into the nozzle.

Abstract: A method and apparatus for measuring the velocity of a fluid relatively independently of the physical properties of the fluid. This is preferably accomplished by spacing two sensor elements at different distances from a heater element. The present invention also contemplates minimizing the effects of the non-zero heater time lag and/or the non-zero sensor time lag for increased accuracy. This is preferably accomplished by either measuring the time lags and subtracting the values thereof from an uncorrected transit time measurement, forcing the sensor elements to track the thermal disturbance in the fluid thereby minimizing the effects of the sensor time lags, or measuring the transit time using sensors that have substantially zero thermal mass.