Abstract: A microactuator array device, which includes a plurality of generally parallel thin flexible polymer sheets bonded together in a predetermined pattern to form an array of unit cells on at least one layer. Thin conductive and dielectric films are deposited on the sheets to form a plurality of electrodes associated with the array of unit cells. A source of electric potential operably connects the electrodes, whereby electrostatic forces are generated most intensely proximate the point where the gap between the sheets is smallest. Inlets and outlets for each cell permit displacement of fluid during generation of the electrostatic forces. In a preferred embodiment, the plurality of sheets forms a stack of layers of arrays of unit cells. The layers are configured such that bi-directional activation is caused by pairs of actuators working opposite each other.

Abstract: A differential gyrator based filter is disclosed that preferably has a first gyrator connected to the positive input signal of the differential input signal and a second gyrator connected to the negative input signal of the differential input signal. A load capacitor is connected between the load terminals of the first gyrator and second gyrator, which minimizes the total load capacitance required for the gyrator based filter. This implementation is believed to increase the overall density, reliability, yield, signal-to-noise ratio and dynamic range of the gyrator based filter and related circuitry.

Abstract: An illumination system having a hollow waveguide including first and second light directing arrays (LDA), each having a plurality of generally lenticular prisms defined thereon and arranged generally orthogonally with respect to each other. Light rays from a light source enter the waveguide through a light input side and emerge from the waveguide through a light output side at a predetermined flux and angular distribution. The light output flux and angular distribution can each be independently controlled in accordance with the present invention by the LDAs to provide an illumination system that can be configured for various light output distribution and intensity requirements.

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 viscometer having a fluid volume-displacer or driver, such as a speaker membrane, and a pressure sensor or detector, such as a microphone membrane, forming the inside surfaces of a cavity that is sealed from the ambient environment of the viscometer except for a controlled leak such as a capillary tube. An electrical signal from the sensor or detector is processed to indicate viscosity of the fluid in the cavity. Additionally determined from the viscosity are heating value, oxygen demand and other thermophysical properties of the fluid. Also, absolute pressure is derived after viscosity is determined.

Abstract: A vertically integrated magnetic memory with Hall effect sensing or reading. It has a ferromagnetic structure with a nearly enclosed magnetic path, which is a vertical structure integrated on a chip. Each memory cell has a closed magnetic field that has high strength for a strong Hall effect. The magnet is a closed loop, robust reproducible magnet. A memory array of such cells uses little power in that only few cells need to draw the read current for a short time required to read the information. A silicon or GaAs chip implementation of the memory is one embodiment, among others, wherein the field required to saturate the electrons can be achieved without excessive power.

Abstract: The invention relates to a micro-optic switch used for transmitting optical signals between optical fibers. More particularly, the invention pertains to a micro-optic switch using polymer structures to position a microactuator and optical fibers on a substrate so that the microactuator can move an optical fiber cantilever between two fixed fibers to transmit optical signals between either one of the fixed fibers and the cantilever fiber. Using polymers instead of micromachined structures to position components of the switch reduces cost and simplifies assembly. The invention further provides processes for producing a micro-optic switch and for switching the path of an optical signal.

Abstract: The reflectivity of a substrate can be improved by combining a reflective diffuse layer with a specular layer. The light output of individual light sources can be improved by embedding them in a composite diffuse and specular substrate resulting in a superior illumination source. A tapered coupling waveguide having a large input surface can be used to couple the illumination source to a thin waveguide having a relatively small input surface area.

Abstract: An optical illumination system is comprised of: (a) a light source means having a reflective emitting surface and an intrinsic luminance (brightness), (b) a light transmitting means; (c) a light reflecting means to reflect and recycle a portion of the light emitted by the light source means back to the light source means; and (d) a light extracting means to extract a portion of the light from the light transmitting means and direct the light to the output of the illumination system. The resulting illumination system achieves an enhanced output luminance. Under certain conditions, it is possible to achieve an output luminance that is greater than the intrinsic luminance of the bare light source.

Abstract: A GaN/AlGaN heterojunction bipolar phototransistor having AlGaN contact, i-GaN absorbing, p-GaN base and n-GaN emitter layers formed, in that order, on a UV transparent substrate. The phototransistor has a gain greater than 10.sup.5. From 360 nm to 400 nm, eight orders of magnitude drop in responsivity was achieved. The phototransistor features a rapid electrical quenching of persistent photoconductivity, and exhibits high dark impedance and no DC drift. By changing the frequency of the quenching cycles, the detection speed of the phototransistor can be adjusted to accommodate specific applications. These results represent an internal gain UV detector with significantly improved performance over GaN based photo conductors.

Abstract: A monolithic, bi-directional micro device formed on a support base, for example a silicon wafer, including at least one input and output flow channels for flow of fluid. The actuator portion includes electrically conducting upper lower diaphragms (preferably formed from doped polycrystalline silicon) formed about a central electrode and mounted on the base. The diaphragms move under electrostatic force between first and second positions upon application of voltage. The upper and lower diaphragms form a sealed, enclosed cavity separated from the channels. The diaphragms are connected for mechanically transmitting electrostatically induced force from one diaphragm to the other, preferably by one or more posts passing through at least one hole formed in the central electrode. The lower diaphragm and the support base are maintained at the same electrical potential. The device is formed by depositing and patterning the electrodes and forming spaces between the electrodes by etching of sacrificial layers.

Abstract: A coating comprised of a broadband transparent binder and multilayer thin film particles is applied to the surface of an object. Each particle has a flat principal surface and the dimensions of the particles are selected so that the flat surface of essentially every particle will align parallel to the nearest portion of the object surface to the particle. There is a leafing or an overlap of the particles parallel to the object surface. The particles form a continuous conformal coating over the object surface. It is preferred that the maximum dimension of the principal surface of each particle be at least 30 microns and, for best results the maximum dimension should exceed 50 microns. Metallic flakes and/or flakes or particles comprised of organic dyes may be included in the coating to further tailor its spectral characteristics. It is preferred that the weight of the particles equals 20 to 40% of the weight of the combination of the particles and the binder.

Abstract: A GPS receiver fault detection method for use in a GPS attitude determination system having Q Receivers, wherein Q>3, includes providing R attitude solutions using subsets of P Receivers and signals from two or more space vehicles, wherein 3.ltoreq.P.ltoreq.Q-1. Post-update measurement residual sets equal to the number R of attitude solutions are determined. Each of the post-update measurement residual sets corresponds to one of the attitude solutions. "S" Receiver faults are detected by comparing the R post-update measurement residual sets, wherein 1.ltoreq.S.ltoreq.Q-3. A faulty Receiver detection system for carrying out the method is also described.

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 batch polymerization process controller using inferential sensing to determine the integral reaction heat which in turn is used to indicate the degree of polymerization of the reaction mixture batch. The system uses a reaction temperature compared with a desired temperature, and the result is used as a feedback to monitor and control the process. One version of the process controller also uses a feedforward signal which is an integral reaction heat indication from a process model. In another version of the process controller, the integral reaction heat is compared with a desired integral reaction heat, and result is used as another feedback to monitor and control the process. Heat production and reaction temperature profiles may be used, along with the thermokinetic equations to determine the polymerization process and reactor models which are utilized by the process controller to optimize the polymerization process in terms of efficient use of cooling water and desired polymerization of each mixture batch.

Abstract: An illumination system has separate components for extracting and directing light from a waveguide. The system eliminates the need to provide a light directing array (LDA) that is optically and physically coupled to the waveguide. It is more reliable and robust than previous illumination systems and virtually eliminates the failures associated illumination systems having laminated LDAs. Manufacturing costs are reduced and system performance and reliability are improved. The illumination system is inexpensive to construct, and operates in an efficient, reliable manner, affording extended service at low cost.

Abstract: A rigid alignment of a fixture connection to a chip having the rigidity of the connection transferred from the chip to a chip holder. The chip has an alignment feature that has a specific position relative to a device on the chip to which another device of a fixture is to be aligned. An alignment fixture has an alignment feature and a device site which aligns with the alignment feature and the device on the chip, respectively. The alignment fixture has a fastener on the chip holder. The chip is moveable on the holder and is moved until the alignment features of the fixture are aligned, which also results in the alignment of the device site with the device. The chip is attached with glue or solder to the holder. The alignment fixture is removed and substituted with a connector interface fixture having no alignment feature relative to the chip but rather an alignment mechanism to the block that the chip is attached.

Abstract: A dual function pixel of an array, having a large fill factor, for detecting visible light and infrared radiation through the same surface area of the pixel. Infrared radiation is absorbed by a conductive oxide layer. This absorbing layer heats up a heat detection layer which thereby indicates the impingement infrared radiation. An infrared reflecting layer made from a conductive oxide reflects infrared light passing through the absorbing layer, back to the absorbing layer. Visible light can pass through all of the layers of the pixel, which are optically transparent, to a visible light detector situated in the substrate of each pixel of the array.

Abstract: A method for use in vehicle attitude determination includes generating GPS attitude solutions for a vehicle using three or more antennas receiving GPS signals from two or more space vehicles. An inertial navigation system is initialized by setting the attitude of the inertial navigation system to a GPS attitude solution generated for the vehicle and/or the attitude of the inertial navigation system is updated using the GPS attitude solutions generated for the vehicle or GPS estimated attitude error generated for the vehicle. A system for use in vehicle navigation is also provided.

Abstract: An acoustic rotor monitor that is an autonomous self-powered measurement instrument which can detect embedded and hidden fatigue cracks in remotely inaccessible devices such as helicopter rotor system components. A predictive maintenance-related problem for rotor craft is the detection of fatigue cracks as a continuous real-time monitoring process under dynamic rotor system loading conditions. The rotor monitor focuses on the embedding an acoustic emission-based smart sensor directly into the rotor system to measure the high frequency stress waves indicating that a structural crack has propagated as a "self-powered" measurement without reducing structural integrity.