Abstract: A modular sensing station architecture that supports flexible power management includes one or more sensors connected to a WINS node. Each node includes power supply, data acquisition, programmable microprocessor and wireless transceiver modules that communicate data and instructions over a bus. The bus suitably includes a signal bus for communicating instructions and low bandwidth data and a high-capacity data bus for transferring high bandwidth data and executing high power tasks. The dual bus approach provides constant communications among the modules and low-capacity data transfer with the option to activate the high-power circuits or tasks only as needed.

Abstract: A reversible electrochemical mirror (REM) includes a first electrode and a second electrode, one of which is substantially transparent to at least a portion of the spectrum of electromagnetic radiation. An essentially nonaqueous electrolytic solution, disposed between the first and second electrodes, contains ions of an electrodepositable metal having a molar concentration of more than 0.5 M. The electrolytic solution also contains halide and/or pseudohalide anions having a total molar concentration ratio of at least 2:1 relative to the concentration of the electrodepositable metal cations. A negative electrical potential applied to the first electrode causes deposited metal to be dissolved from the second electrode into the electrolytic solution and to be electrodeposited from the solution onto the first electrode to form a mirror deposit, thereby affecting the reflectivity of the REM device for electromagnetic radiation.

Abstract: Electrochemical surface analysis using a deoxygenated gel electrolyte provides advantages over a liquid electrolyte in processes such as sequential electrochemical reduction analysis. In sequential electrochemical reduction analysis, a solderable portion of an electronic component or circuit board to be tested is placed in contact with a deoxygenated gel electrolyte such as a borate buffer solution having a gelling agent. The gel electrolyte prevents capillary attraction up or along a lead of the component so that the power source cathode lead does not contact the electrolyte and electrochemical analysis can be localized to the area of interest, such as the portion of the component lead to be soldered. Interfering effects of atmospheric oxygen are minimized for deaerated gel electrolytes because convection mixing is practically absent and diffusion is generally a very slow process in a gel.

Abstract: An electrochemical mirror includes a transparent first electrode and a second electrode. An electrolytic solution, disposed between the first and second electrodes, contains ions of a metal which can electrodeposit on the electrodes. A negative electrical potential applied to the first electrode causes deposited metal to be dissolved from the second electrode into the electrolytic solution and to be electrodeposited from the solution onto the first electrode, thereby affecting the reflectivity of the mirror for electromagnetic radiation. A surface modification layer applied to the first electrode ensures that the electrodeposit is substantially uniform, resulting in a mirror layer which increases the reflectivity of the mirror. A positive electrical potential applied to the first electrode causes deposited metal to be dissolved from the first electrode and electrodeposited from the solution onto the second electrode, thereby decreasing the reflectivity of the mirror.

Abstract: An O-plate compensator comprising an organic liquid crystal polymer, and methods for fabricating the same, are disclosed. The compensator is a uniaxial birefringent thin film with its extraordinary axis oriented obliquely with respect to the surface of the film. (It is noted that the birefringent thin film could be weakly biaxial.) The oblique orientation of the liquid crystal director, which is parallel to the film's extraordinary axis, is achieved by casting an organic thin film onto a surface specially prepared for orienting liquid crystals, such as obliquely deposited SiO, mechanically rubbed alignment agents. The film can either be cast from a solution of the liquid crystal polymer or from a reactive liquid crystal monomer having a nematic phase. Any solvent that may be used during the fabrication process is evaporated off and the organic thin film is held at a temperature in its nematic phase. If a reactive monomer is used, the film is then photopolymerized.

Abstract: A normally white liquid crystal display includes polarizer and analyzer layers having perpendicular absorbing axes. A liquid crystal layer is disposed between the polarizer layer and the analyzer layer, with its director exhibiting an azimuthal twist through the layer. First and second electrodes are proximate to first and second major surfaces of the liquid crystal layer. A first negatively birefringent compensator layer, oriented with its optical axis substantially parallel to the average direction of the optical axis within a central, nominally homeotropic region of the liquid crystal layer in its driven state, is disposed between the polarizer layer and the liquid crystal layer. A second negatively birefringent compensator layer, with a birefringence substantially the same as the birefringence of the first compensator layer and oriented with its optical axis substantially parallel to the optical axis of the first compensator layer, is disposed between the analyzer layer and the liquid crystal layer.

Abstract: A normally white super-twist nematic liquid crystal display is disclosed. Between a polarizer layer and an analyzer layer, the display includes a super-twist nematic liquid crystal cell having first and second substrates and a liquid crystal layer disposed between the first and second substrates. The display further includes at least one positively birefringent A-plate compensator layer disposed between the polarizer layer and the super-twist nematic liquid crystal cell and at least one positively birefringent A-plate compensator layer disposed between the analyzer layer and the super-twist nematic liquid crystal cell to reduce chromaticity shifts of the display at wide viewing angles and over temperature variations.

Abstract: A piezoelectric device or actuator (30) includes dimorph stack (32) attached to a support (34). Affixed to the apex of stack (32) is friction surface (36) which is held in contact with the external friction surface of a positionable object (38).

Abstract: A method to fabricate a photo-patterned organic compensator for liquid crystal displays, and the resulting compensator structure, are described. One illustrative fabrication method comprise: (1) depositing a thin film of polymerizable liquid crystal material onto one of a display's substrates; (2) orienting the liquid crystal material's director to a specified direction; (3) polymerizing the deposited thin film through an aperture mask; (4) removing the aperture mask; and (5) curing/annealing the thin film layer to yield a planar structure having substantially birefringent and isotropic regions. Complete pixelated compensators may be created by layering two or more such two-region thin films.

Abstract: An electrochemical mirror includes a transparent first electrode and a second electrode distributed in localized areas. An electrolytic solution is disposed between the first and second electrodes and contains ions of a metal which can electrodeposit on the first and second electrodes. A negative electrical potential applied to the first electrode causes deposited metal to be dissolved from the second electrode into the electrolytic solution and to be electrodeposited from the solution onto the first electrode, thereby affecting the propagation of electromagnetic radiation through the mirror. A surface modification layer applied to the first electrode ensures that the electrodeposit is substantially uniform, resulting in a mirror layer which increases the reflectivity of the mirror.

Abstract: An electrochemical device includes a transparent first electrode and a second electrode distributed in localized areas. An electrolytic solution, disposed between and in electrical contact with the first and second electrodes, contains ions of a metal which can electrodeposit on the first and second electrodes. Atoms of this metal are deposited on the first or the second electrode. A negative electrical potential applied to the first electrode causes deposited metal to be dissolved from the second electrode into the electrolytic solution and to be electrodeposited from the solution onto the first electrode, thereby affecting the propagation of electromagnetic radiation through the device. Conversely, a positive electrical potential applied to the first electrode causes deposited metal to be dissolved from the first electrode and electrodeposited from the solution onto the second electrode, thereby increasing the transmissivity of the device.

Abstract: A CMOS imaging system provides low noise read out and amplification for an array of passive pixels, each of which comprises a photodetector, an access MOSFET, and a second MOSFET that functions as a signal overflow shunt and a means for electrically injecting a test signal. The read out circuit for each column of pixels includes a high gain, wide bandwidth, CMOS differential amplifier, a reset switch and selectable feedback capacitors, selectable load capacitors, correlated double sampling and sample-and-hold circuits, an optional pipelining circuit, and an offset cancellation circuit connected to an output bus to suppress the input offset nonuniformity of the amplifier. For full process compatibility with standard silicided submicron CMOS and to maximize yield and minimize die cost, each photodiode may comprise the lightly doped source of its access MOSFET. Circuit complexity is restricted to the column buffers, which exploit signal processing capability inherent in CMOS.

Abstract: Data which represents an animation sequence of a three dimensional object at a series of discrete time frames is compressed by identifying characteristic features of the object; generating a quadrangular mesh representation of the object, whereby the object is mathematically defined by dividing it into one or more regions and hierarchically representing each region by a mesh, each mesh including three coordinate matrices which define the positions of nodes within the mesh; selecting from the mesh representation of the features a set of animation parameters which are capable of specifying changes in the mesh corresponding to the animation of the object; compressing each region mesh by applying pyramid progressive coding to the coordinate matrices for the mesh; storing the initial values for the animation parameters at the beginning of the animation sequence; and, at each time frame after the beginning of the animation sequence, estimating the current values of the parameters and compressing each parameter by e

Abstract: A suspended microstructure process assembly includes a first microstructure assembly, with a temporary substrate having a first surface and a first microstructure fabricated on the first surface; a second microstructure assembly, including a final substrate having a second surface and a second microstructure fabricated on the second surface; connecting elements for joining the first microstructure assembly to the second microstructure assembly with a predetermined separation and alignment; and a removable bond temporarily securing the first microstructure assembly to the second microstructure assembly until the temporary substrate is removed. The connecting elements may be electrically conductive contacts or electrically nonconductive spacers. Electrically conductive contacts may be supplied to the first microstructure from a back side of the first microstructure assembly. The first microstructure fabricated on the first surface may incorporate a removable layer to enable multiple level suspended structures.

Abstract: A liquid crystal display for viewing at various angles with respect to a normal axis perpendicular to the display includes a polarizer layer having an absorbing axis, an analyzer layer having an absorbing axis substantially perpendicular to the absorbing axis of the polarizer layer, a liquid crystal layer disposed between the polarizer layer and the analyzer layer and having a director exhibiting an azimuthal twist through the layer with respect to the normal axis, a first electrode proximate to a first major surface of the liquid crystal layer, a second electrode proximate to a second major surface of the liquid crystal layer, the first and second electrodes being adapted to apply a voltage across the liquid crystal layer when the electrodes are connected to a source of electrical potential, and a compensator, including a positively birefringent O-plate compensator layer disposed between the polarizer layer and the analyzer layer with its principal symmetry axis oriented at a substantially oblique angle with

Abstract: An interferometrically readable optical encoder for sensing linear position includes an optical medium movable in a linear direction and having a data storage layer, a plurality of uniformly sized sectors being defined in the layer. A linear absolute track is defined in the layer parallel to the linear direction and a plurality of absolute marks is formed in the layer in sequence along the absolute track within each sector, each such absolute mark being detectable by interferometric reflection of coherent light as representative of a binary 1 or a binary 0 and each such plurality of absolute marks defining a binary word. A linear incremental track is defined in the layer parallel to the linear direction with a series of incremental marks formed in the layer and evenly spaced along the first incremental track, each such incremental mark being detectable by interferometric reflection of coherent light.

Abstract: An ambient temperature solid state sensor for detecting the concentration of a gas includes an insulating substrate, a polycrystalline semiconducting oxide thin film deposited on the substrate such that the gas can be adsorbed on the surface of the film, the film having a low carrier concentration and a high resistivity, a pair of electrodes disposed on the film for measuring the electrical resistance of the film, and a source of light having a wavelength component which is absorbed by the thin film, thereby causing photodesorption of the gas from the surface of the film and establishing the equilibrium between gaseous species in the ambient and gaseous species adsorbed on the oxide surface. The resistance of the thin film is dependent on the amount of adsorbed gas, the measured resistance of the film thereby indicating the concentration of the gas.

Abstract: Power is provided to a fluorescent lamp by connecting a source of alternating electrical current, consisting of a series of alternately positive and negative current pulses, to the lamp and shaping the current pulses such that the absolute value of the current increases as a function of time within each pulse.

Abstract: A multiple pass band, thin film optical filter includes a first single pass band filter having a first pass band at a first wavelength, with a first quarterwave stack of thin film layers alternating between layers of a first dielectric material having a first refractive index and layers of a second dielectric material having a second refractive index, the optical thickness of each layer in the first stack being substantially one fourth of the first wavelength. A first half wave layer is interposed within the first stack and has an optical thickness which is an integral multiple of one half of the first wavelength, such that the reflectivities of the portions of the first stack on either side of the first half wave layer are substantially identical.

Abstract: A monolithic O-plate optical compensator device, in accordance with the invention, comprises a plurality of thin-film compensation layers which are deposited on a single substrate. As used herein, the term “monolithic” is meant to imply that the O-plate and other thin-film compensator layers are formed by depositing (e.g., via solvent casting or vacuum deposition) one layer on top of another layer; with or without the use of surface modification treatments such as adhesion layers, alignment layers, and the like.