Abstract: This invention relates to processes for the assembly of three-dimensional structures having periodicities on the scale of optical wavelengths, and at both smaller and larger dimensions, as well as compositions and applications therefore. Invention embodiments involve the self assembly of three-dimensionally periodic arrays of spherical particles, the processing of these arrays so that both infiltration and extraction processes can occur, one or more infiltration steps for these periodic arrays, and, in some instances, extraction steps. The product articles are three-dimensionally periodic on a scale where conventional processing methods cannot be used.

Abstract: An active region of a VCSEL at one (i.e., n doped) end having an expanded effectively undoped region, and another (i.e., p doped) end having a significantly doped region up to or even including a portion of the active region. A previous way had heavy doping of the n and p doped regions up to the active region, at least close to it or even partially into it.

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 sensor device for detecting vibration, including a light source for providing a laser light, a first optical fiber connected to the source for transmitting the laser light, an oscillator positioned to receive the transmitted laser light and adapted to reflect the light as a frequency modulated light; a second optical fiber positioned to capture the frequency modulated light to transmit the frequency modulated light; and a frequency modulated discriminator for receiving the frequency modulated light from the second optical fiber and producing a signal responsive of vibration of the oscillator. In a preferred embodiment, the frequency modulated discriminator further includes a frequency meter for determining the average number of cycles per unit time to provide a second signal responsive of the temperature of the oscillator.

Abstract: A device for controlling the proportional pressure or flow of fluids over a range of source pressure. An addressable array is interposed between a source pressure and an exit pressure chamber. The array comprises a plurality of valves, the total open area of which define the opening between the source pressure and the exit pressure. Also provided is an actuator for separately actuating each valve of the array between an open and a closed condition, whereby the total number of open valves determines the flow between the source pressure and the exit pressure. The preferred valves are electrostatically actuated valves including upper and lower electrodes addressable by a conductor, and are fabricated monolithically on a single substrate. The array is formed so that actuation actuates a number of valves ranging from one valve to all the valves in the array. The device may be used to control flow between the source pressure and the exit pressure chamber.

Abstract: A sensor having an active sensing material exposed to the substance to be detected and an active reference material that is shielded from the substance to be detected. Thermocouples having a set of junctions proximate to the active sensing material and another set of junctions to the active reference material for measuring the temperatures at the respective materials. The junctions are connected differentially in that a difference of the two temperatures is measured. A heater is proximate and common to the two materials. Heat pulses may be applied to the materials via the heater and the temperatures are measured. If ambient factors or substances affect the active sensing material, its thermal response will be different than that of the active reference material, and a differential pulse-like indication of temperature will be detected.

Abstract: A programmable output buffer with independently controllable current mirror legs is disclosed. The output buffer includes a current mirror that has a reference leg and a number of current mirror legs. The reference leg is biased using a reference current that is relatively independent of the supply voltage. Each of the current mirror legs is coupled to the output terminal of the output buffer, and conducts a current that is proportional to the reference current. This produces an output current that is relatively independent of variations in the supply voltage. To provide a programmable output power level, each of the current mirror legs are separately enabled. By controlling which of the current mirror legs are enabled, the output power of the output buffer can be controlled.

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.

Abstract: A method and apparatus for determining selected fluid properties using a self-oscillating fluid sensor. In a preferred embodiment, a sensor is provided that oscillates at a frequency that is related to the transit time of a temperature disturbance through the fluid. Based on the transit time, selected fluid properties of the fluid can be determined.

Abstract: Improved linear illumination sources which utilize external, highly reflective enclosures containing one or more linear openings and thereby achieve improved source efficiency, output irradiance and/or output radiance. Such improved illumination sources may be combined with additional optical elements to produce more complex illumination systems.

Abstract: The present invention overcomes many of the disadvantages of the prior art by providing a display that can be calibrated and re-calibrated with a minimal amount of manual intervention. To accomplish this, the present invention provides one or more cameras to capture an image that is projected on a display screen. In one embodiment, the one or more cameras are placed on the same side of the screen as the projectors. In another embodiment, an array of cameras is provided on either or both sides of the screen for capturing a number of adjacent and/or overlapping capture images of the screen. In either of these embodiments, the resulting capture images are processed to identify any non-desirable characteristics including any visible artifacts such as seams, bands, rings, etc. Once the non-desirable characteristics are identified, an appropriate transformation function is determined.

Abstract: A system for sealing a building air duct in response to a chemical or biological attack to prevent the building HVAC system from delivering the chemical or biological agent throughout the building. The system can include an inflatable bladder for disposition within an air duct, a source of gas for expanding the bladder, an initiator for initiating the gas expansion, and a detector for detecting the agent. One bladder is formed of a resilient material suitable for extending into duct corners. Another bladder is larger than the duct to be sealed and is formed of a non-resilient material capable of inflating and bunching into duct corners. One source of gas is a gas canister while another source of gas is a chemical composition capable of reacting and forming the gas. One bladder includes a foaming agent which can expand and solidify within the bladder. One initiator utilizes an electronic signal to initiate the gas expansion. Another initiator includes use of an RF signal to initiate the gas expansion.

Abstract: An actuator device providing an active surface. The actuator has a base having at least one first electrostatic electrode mounted therein which is oriented for electrostatic cooperative action with an opposing electrostatic electrode in a cover mounted above the first electrostatic electrode to define an enclosed cavity. The cover has at least one second electrostatic electrode for cooperative electrostatic activation between the electrostatic electrodes. The cover also has an outer surface forming the active surface. A power supply is operably connected to the electrostatic electrodes for causing the cooperative electrostatic activation. A quantity of fluid is contained within the cavity for pneumatically defining active surface conditions during cooperative electrostatic actuation. The cavity may be closed to provide a sealed cavity for movement of the fluid, either a gas or a liquid, during the cooperative electrostatic actuation, or it may be open to the atmosphere.

Abstract: A structure and method of making resistive emitting members which exhibit high resistivity while at the same time providing high temperature operation significantly above that known in the art. Specifically the use of nitrides of Group IVB transition metals from the periodic table, exclusive of titanium is described.

Abstract: An electrostatic actuator and drive configuration device for use in a system requiring a long term ON state operation. The device includes a first electrostatic actuator positioned to operate in the system requiring the long term ON state upon activation of a power supply. The device also includes a second electrostatic actuator positioned to operate in the system requiring the long term ON state upon activation of the power supply. A timer is connected to the power supply to alternately select the first or the second actuator for activation to drive the selected actuator to the ON state. The timer is controlled to select the first or second electrostatic actuator on an alternating basis to prevent either electrostatic actuator from remaining in the ON state for more than a predetermined time without the other actuator being selected. The electrostatic actuators may be configured in parallel or in series, depending upon the demands of the system.

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.

Abstract: Improved linear illumination sources are disclosed which utilize external, highly reflective enclosures containing one or more linear openings and thereby achieve improved source efficiency, output irradiance and/or output radiance. Such improved illumination sources may be combined with additional optical elements to produce more complex illumination systems.

Abstract: A method for scheduling periodic incremental and design to time processes. The algorithm is based on the slack stealer which dynamically determines the remaining slack time after all periodic processes are scheduled utilizing Rate Monotonic Scheduling (RMS). An incremental process determines how much execution time is available after the baseline component has completed and prior to the execution of a process increment. A design to time process determines how much execution time is available before the process begins execution and selects a version which gives the greatest precision in the available time. For both incremental and design to time processes, a minimum amount of time is statically reserved so that an acceptable but suboptimal solution will always be calculated. The solution identifies and proposes solutions for the practical problem of supporting criticalities when scheduling slack and analyzing the run-time overheads.

Abstract: An electrostatic actuator array having at least one cell, in which the individual cells share a common electrode. Each cell includes first and second electrodes separated by a distance and having a moveable diaphragm mounted there between for conducting a voltage potential thereto. One of the pair is movable with respect to the other, and the pair are positioned to move upon application of a voltage potential thereto by electrodes attached thereto. A voltage potential producing an alternate polarity field generated from a single DC power supply is selectively provided to the electrodes to cause the movement. The preferred signals from the power supply are uni-polar square wave signals, preferably deriving the alternate polarity field from a DC current having time allocation of signals to present alternating fields to each actuator. The individual cells are configured in an actuator array wherein some cells operate out of phase with adjoining cells.

Abstract: An array for projecting thermal images and a method of making same. The array of the present invention combines a two-tier architecture created with special processing whereby each pixel member resides on an elevated platform directly over discrete pixel control electronics and electrically conducting traces couple a plurality of pixels so that they can be controlled to project thermal images at equal to or faster than video frame rates. Microlens assemblies coupled to each discrete pixel improves the thermal efficiency of the array for certain applications. In the method of fabrication, a semiconductor microbridge-type structure obtains with the use of sacrificial layers under deposited pixel members in a compact array so that the pixel electronics reside beneath their associated pixel and the array electronics inhabit the same chip as the array thereby improving fill factor and time constant of the resulting array.