Abstract: A thermal isolation microstructure fabricated by a process which allows the ultra thinning of support legs for the microdetector.

Abstract: A microstructure design for high IR sensitivity having a two level infrared bolometer microstructure, the lower level having a reflective metal film surface such as Pt, Au, or Al to reflect IR penetrating to that level, the upper level being separated from the lower level by an air gap of about 1-2 microns which allows the reflected IR to interfere with the incident IR and increase the sensitivity to a higher level.

Abstract: The invention relates to a problem-state monitoring system which includes an automated reasoning technique for providing moment-by-moment advice concerning the operation of a process. The reasoning technique involves the representation of states a problem can attain during the problem solving process which provides greater flexibility for the monitoring and advisory functions.

Abstract: A non membrane-based overpressure proof gas pressure microsensor. It is not a membrane-based microsensor but is based on an open microbridge sensor structure. A method and apparatus is described to determine gas pressure from thermal conductivity, k, and volumetric specific heat, c.sub.pu, as well as pressure, P, using a microbridge sensor.

Abstract: A method of determination of gas properties at reference conditions of temperature and pressure. This determination is needed in systems including mass flow meters, combustion control systems, gas meters and the like. The system disclosed enables the determination of properties including specific heat and thermal conductivity at reference conditions.

Abstract: A method and system for regulating and maintaining a predetermined desired fuel-air mixture for a fuel of interest as represented by a desired fuel number disclosed which utilizes a known relationship between the radiation intensity ratios of selected chemical species in the products of combustion and the fuel number as a basis to adjust the proportion of fuel within the fuel-air mixture to control at the desired fuel number.

Abstract: The instant invention provides a method and system for dehumidifying air by microphorous organic hollow fibers having a hygroscopic liquid disposed in the pores thereof for providing a concentration gradient sufficient to provide a continuous water removal mechanism.

Abstract: A microbridge air flow sensor which has a sealed etched cavity beneath the silicon nitride diaphragm so that the cavity is not susceptible to contamination from residual films or other material accumulating within the cavity. The cavity thermally isolates the heater and detectors which are encapsulated in the diaphragm. The cavity is fabricated by front side etching of the silicon wafer. Narrow slots are made through the silicon nitride diaphragm to expose a thin film (400 angstrom) rectangle of aluminum. A first etch removes the aluminum leaving a 400 angstrom very shallow cavity under the diaphragm. Anisotropic etch is then introduced into the shallow cavity to etch the silicon pit.

Abstract: An improved connector pad stack structure for use in microstructure devices having a silicon nitride surface in which the sensor metal such as platinum or Ni-Fe is eliminated from the pad bonding site and only adhesion promoting metals are used on the Si.sub.3 N.sub.4 to provide a stronger, more durable and reliable pad stack.

Abstract: The invention relates to a coefficient of performance deviation meter for vapor compression type refrigeration systems. The measurement of the coefficient of performance of a mechanical vapor compression refrigeration system requires that the two parameters be known which are the input power and the heat absorbed or, conversely, the input power and the heat rejected. Manufacturers of vapor compression machines publish performance data on the power used versus the cooling effect at various condenser water supply temperature (Tcws) and various evaporator chilled water supply temperature (Tchws). These data can be used to calculate specific coefficients of performance (COPs) at various Tcws and Tchws. The meter has inputs connected to sensors in a vapor compression system which provide the data for the input power and the heat absorbed parameters. One input is connected to a wattmeter set in the compressor motor power supply circuit which provides the input power.

Abstract: Certain relationships among the mass flow signal the thermal conductivity, specific heat and density of the fluid measured can be used to correct a mass flowmeter measurement with respect to changes in composition of the fluid.

Abstract: A complementary (Al,Ga)As/GaAs heterostructure insulated gate field-effect transistor (HIGFET) approach is described in which both the n-channel and p-channel transistors utilize a two-dimensional electron (hole) gas in undoped high mobility channels to form planar, complementary GaAs-based integrated circuits.

Abstract: An improved FET capacitance driver logic circuit having an inverter feedback stage 22 connected from output to input of output FET 23 to allow the output FET to have a large capacitance charging current surge followed by a reduced conduction thereafter.

Abstract: A microbridge air flow sensor having a silicon nitride diaphragm formed on the surface of a single crystal silicon wafer. A rectangular 500 angstrom thick sacrificial layer was deposited on the silicon surface before the silicon nitride to define the exact position of the diaphragm. A series of etches from the backside of the wafer is performed to fabricate the device. A first silicon anisotropic etch from the backside is stopped at the sacrificial layer. A sacrificial layer selective etch is applied from the backside first pit to the sacrificial layer to remove all of the rectangular sacrificial layer. Anisotropic etch is again applied into the space created by the removed sacrificial layer whereby the second etch attacks the silicon exposed by the removal of the sacrificial layer and etches downward forming a second anisotropic etch pit. Thus all the etches are from the backside of the silicon wafer.

Abstract: A color mark sensor utilizing the cumulative chromatic aberration in an extended planar gradient-index (GRIN) lens to provide unambiguous primary color separation in a continuum along the lens axis. An appropriately chosen GRIN lens length provides separation and focus of any primary color from the general polychromatic background.

Abstract: This invention discloses an optical interconnect structure for routing and distributing optical signals on silicon chip carriers to realize high-density packaged optical interconnects for discrete GaAs optoelectronic IC's.

Abstract: A remote passive condition sensor apparatus such as a temperature or humidity sensor apparatus. A corner cube reflector at a remote location, where it is not feasible to have electrical connections or batteries, receives and reflects back radiant energy to an optical readout instrument. Condition responsive elements in the corner reflector affect the amount of reflected radiant energy as a function of the condition sensed.

Abstract: A two-dimensional bolometer array having electronic array uniformity correction. The individual resistive sensors in the bolometer array are not electrically uniform and uniformity is a requirement to permit efficient electrical readout of signals. An electronic correction circuit in this invention automatically corrects for non-uniformity in the array.

Abstract: The sensors and heater of a microbridge flow sensor are each compensated for non-linear curvature of the resistance versus temperature curve by the use of a section of permalloy in series with a section of platinum thin film resistor. The platinum exhibits non-linearity in one direction and the permalloy exhibits non-linearity in the opposite direction.

Abstract: A low power complementary (Al,Ga)As/GaAs heterostructure insulated gate field-effect transistor (HIGFET) approach is described in which the n-channel transistor utilizes an In.sub.x Ga.sub.1-x As semiconductor gate to reduce threshold voltage (V.sub.t) of the n-channel FET to allow low power circuit operation.