Patents Assigned to American Research Corporation of Virginia
  • Patent number: 6521185
    Abstract: A highly-sensitive, rapid response fluorescent probe is based on the affinity of a polymer matrix for an analyte of interest. The probe includes a polymer matrix and a dye immobilized in the matrix. The polymer matrix has an affinity for an analyte of interest and the dye has little or no sensitivity to the analyte of interest when excited by an excitation source in a free state but has significant sensitivity to the analyte of interest when excited by the excitation source when immobilized in the matrix. Sensors incorporating the polymer/fluorophore probes of the present invention have the sensitivity and rapid response needed for detection of chemical agent and biological materials. Sensors using the probes provide sensitivity to Sarin at several hundred parts per trillion in one second or less. That is a notable advance over state-of-the-art detectors that require preconcentration steps, which in turn restrict response times to one minute or more.
    Type: Grant
    Filed: October 23, 1995
    Date of Patent: February 18, 2003
    Assignee: American Research Corporation of Virginia
    Inventors: Howard P. Groger, Shufang Luo, K. Peter Lo, Martin Weiss, James M. Sloan, Russell J. Churchill
  • Patent number: 6433299
    Abstract: Magnetic modules and a process for manufacturing magnetic modules are provided wherein magnetic material is deposited into one or more cavities patterned into a non-magnetic substrate die to form a plurality of magnetic cores. The patterned substrate board, which may be a composite of graphite, a composite of alumina or other non-magnetic ceramic, provides a surface for winding windows, inductor air gaps, isolations, and a mounting surface for other system components.
    Type: Grant
    Filed: January 23, 1996
    Date of Patent: August 13, 2002
    Assignee: American Research Corporation of Virginia
    Inventor: Usha Varshney
  • Patent number: 6300638
    Abstract: An instrument for total internal reflection fluorescence spectroscopy having modular probe that inexpensively monitors vapors and liquid-phase analytes under field conditions is described. The system is particularly helpful in evaluating multiple analytes using the fluorescence of a material immobilized in a thin sorbent polymer coating. At the same time, the system is capable of monitoring trace quantities of analyte using a fluorescence-read immunological reaction. The device includes a diode laser source, a shaped optical element (which may be as simple as a microscope slide), and one or more amplified photodiode detectors. The shaped optical element propagates light from the diode laser in a series of internally reflective bounces.
    Type: Grant
    Filed: November 12, 1998
    Date of Patent: October 9, 2001
    Assignees: Calspan SRL Corporation, American Research Corporation of Virginia
    Inventors: Howard P. Groger, John Raymonda, K. Peter Lo, Roger L. Reynolds, William F. Sullivan, Myron T. Coolbaugh
  • Patent number: 6277651
    Abstract: The present sensor allows the user of any diode laser structure to be employed to provide sensitive chemical and biological detector. A diode laser electrochemical sensor is described in U.S. Pat. No. 5,591,407 “Laser Diode Sensor”. The present invention surpasses the capabilities of those sensors by measuring changes in the output power, output spectral characteristics or output signal auto-correlation function to detect the presence of chemical or biological films within the sensitive region.
    Type: Grant
    Filed: July 9, 1998
    Date of Patent: August 21, 2001
    Assignees: Calspan SRL Corporation, American Research Corporation of Virginia
    Inventors: Howard P. Groger, Myron T. Coolbaugh, K. Peter Lo, Russell J. Churchill
  • Patent number: 6207961
    Abstract: An optical fiber fluorescence sensor system capable of compensating fiber bending loss is provided. The system uses a modulated light-emitting diode and digital-signal processing chips to enhance the measurement of fluorescence signals. A fiber-optic oxygen sensor system suitable for measuring oxygen levels in gas and in aqueous media is provided. The system alleviates fiber bending loss. Detection of the signal-to-noise ratio of the system which exceeds 30 dB is done by using inexpensive components.
    Type: Grant
    Filed: October 15, 1997
    Date of Patent: March 27, 2001
    Assignee: American Research Corporation of Virginia
    Inventors: K. Peter Lo, Howard P. Groger, Shufang Luo, Russell J. Churchill
  • Patent number: 6097477
    Abstract: The invention provides a method of triple-beam and triple-sensor in a laser speckle strain/deformation measurement system. The triple-beam/triple-camera configuration combined with sequential timing of laser beam shutters is capable of providing indications of surface strain and structure deformations. The strain and deformation quantities, the four variables of surface strain, in-plane displacement, out-of-plane displacement and tilt, are determined in closed form solutions.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: August 1, 2000
    Assignee: American Research Corporation of Virginia
    Inventor: Adel K. Sarrafzadeh-Khoee
  • Patent number: 6051437
    Abstract: Optical chemical probes have layers of anionic and cationic polyelectrolytes and one or more dyes incorporated into these layers. The probes are placed into the medium and the dye or dyes react in the presence of the corresponding chemical. Color changes may be observed manually or by a photo detector. A light source may be employed to increase the optical signal received from the probe. Further, a waveguide may be used to trap multiple optical signals. The invention is used for chemical analysis.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: April 18, 2000
    Assignee: American Research Corporation of Virginia
    Inventors: Shufang Luo, K. Peter Lo, Howard P. Groger, Russell J. Churchill
  • Patent number: 5973441
    Abstract: The vibration and electrical characterization of a piezoelectric tactor actuator is described. The actuator is a rectangular laminated flat plate with two opposite sides simply supported and two others free. Under an axial compression from the supports, the plate deforms into a stressed shallow shell. Electrical high frequency harmonic signals within relatively low-frequency bursts are applied to the piezoelectric layers. Depending on the axial compression and pre-deflection, frequency and magnitude of electrical input, the tunable actuator exhibits frequency/mode-controlled high-force over large area vibrations with intense displacement jumps. A single-degree-of-freedom model and simplified 1-D models are provided. The tactor provides efficient conversion of electrical energy into mechanical.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: October 26, 1999
    Assignee: American Research Corporation of Virginia
    Inventors: K. Peter Lo, Nicholas V. Nechitailo, Howard J. Moses, Lawrence H. Decker, Howard P. Groger, Russell J. Churchill
  • Patent number: 5850089
    Abstract: Modulated-structure polycrystalline or heteroepitaxial multilayers of PZT/PT ferroelectric thin films are deposited on a substrate, preferably by laser ablation. The laser ablation of the PZT/PT layers onto a prepared substrate occurs while maintaining the substrate at a temperature between 380.degree. C. to about 650.degree. C. The target source for the PZT/PT laser ablated film may be either bulk PZT and PT ceramics or powders or individual metal oxides or metal pellets. The ferroelectric thin film device may be used for a random access memory.
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: December 15, 1998
    Assignee: American Research Corporation of Virginia
    Inventors: Usha Varshney, Angus Ian Kingon
  • Patent number: 5768137
    Abstract: A precision positioning system is used for resurfacing and repairing rails and guideways of large, heavy machinery at users facilities. The system has new components, an entire machining system, a new alignment system, parallel platforms for tool support and surface scanning. A sectioned, portable monorail frame is held by fixed supports at the locus of a heavy machine requiring guideway straightening. Fixed guides extend along the outer surface of the monorail. Guide wheels and drive wheels contact the guides and support and move an outer tubular beam carriage. An assembly of machining tools is adjustably positioned on the carriage. Laser alignment sources and sensors are connected to the carriage and to heavy machines off-axis and parallel to the monorail. Intelligent controls precisely position the tools for resurfacing the rails and guideways. Scanning and a printout of machine guideway accuracy, before and after the operation, provide written verification of quality improvement.
    Type: Grant
    Filed: April 12, 1995
    Date of Patent: June 16, 1998
    Assignees: American Research Corporation of Virginia, Eastern Repair Fabrication
    Inventors: Roger J. Polidoro, Henry M. Bass, Russell J. Churchill, Bruce L. Thomas, Lloyd K. Loftus
  • Patent number: 5757013
    Abstract: An apparatus and its accompanying method measures fluorescence decay, fluorescence amplitude and fluorescence polarization. The instrument includes a light emitting diode or laser diode light source, an amplified photodiode detector, and electronics and software for calculating the phase of the fluorescence from the computed inner product of the scattering and fluorescence signals. The electronics for measuring fluorescence decay includes two signal synthesizers, two downconverters, a simultaneously sampling analog-to-digital converter and means for calculating the inner product of the downconverted waveforms. A signal source, preferably a direct digital synthesizer, is used in combination with a digital-to-analog converter to provide a controllable output signal. That signal drives a modulatable light source, which is a light emitting diode, a laser diode or a combination of the two. Excitation light from the light source excites the sample fluorophore which is immobilized in a solid material.
    Type: Grant
    Filed: December 6, 1995
    Date of Patent: May 26, 1998
    Assignee: American Research Corporation of Virginia
    Inventors: Howard P. Groger, Russell J. Churchill, K. Peter Lo, Shufang Luo
  • Patent number: 5745231
    Abstract: Fluorescence measuring methods and apparatus use planar optical waveguides to excite fluorescence in the evanescent field of the waveguides and photodetectors to sense the fluorescence produced. Chemically sensitive fluorophores are bound to the evanescent regions of the planar optical waveguides. Substrates support the waveguides. Photodetectors, positioned in the substrates with fields of view normal to the waveguides, detect the fluorescence. Wavelength-selective material coating surfaces of the photodetectors allow fluorescence to be detected while restricting entry of light at the excitation wavelengths. The photodetectors have high aspect ratios for detection of fluorescence generated by the optical waveguides. Preferably, the photodetectors are closely coupled to the fluorescence generated in the evanescent field of the waveguide.
    Type: Grant
    Filed: June 12, 1995
    Date of Patent: April 28, 1998
    Assignee: American Research Corporation of Virginia
    Inventors: Howard P. Groger, K. Peter Lo, Martin Weiss
  • Patent number: 5685721
    Abstract: A refreshable braille cell display uses a single moving part per tactile element. Tactile elements, formed from stainless steel tubing, are assembled in densely arranged modules. Lower ends of the tactile elements extend beneath the modules and are in contact with a pressurized medium. Shape memory alloy actuators are positioned in the tactile elements, isolated from any motion or flow in the pressurized medium. When a pressurized medium is delivered through a port in a tactile element, the actuator extends upward, thereby forcing the upper portion of the tactile element through a hole in the user contact surface. In that state the tactile element indicates information. When the tactile element is activated, current flows from an electrical contact at the lower end of the tactile element, through the actuator, and into the outer tube of the tactile element. The actuator heats, due to electrical resistance, contracts and exerts a downward force on the pressure medium.
    Type: Grant
    Filed: November 6, 1995
    Date of Patent: November 11, 1997
    Assignee: American Research Corporation of Virginia
    Inventor: Lawrence H. Decker
  • Patent number: 5626670
    Abstract: A method for developing large area highly oriented polycrystalline ferroelectric thin films using spin-on sol-gel deposition and laser crystallization techniques that allow for precise control of temperature distribution. The present invention improves quality, reliability, performance and cost effective production of ferroelectric non-volatile random access memory (FNVRAM) on thermally sensitive silicon and gallium arsenide semiconductor substrates compatible with very large scale integrated circuit technologies. The method is time effective, as crystallization is performed in three seconds as compared to thirteen hours in a conventional furnace for 1 cm.times.1 cm wafer. In addition, crystallization of the film is further achieved without exposing the underneath device structure to detrimental high temperature annealing conditions.
    Type: Grant
    Filed: October 3, 1994
    Date of Patent: May 6, 1997
    Assignee: American Research Corporation of Virginia
    Inventors: Usha Varshney, Angus I. Kingon
  • Patent number: 5606633
    Abstract: A highly sensitive surface plasmon waveguide sensor monitors the refractive index and thickness of thin adsorbed films. The sensor includes an optical waveguide formed by ion-exchange in a glass substrate, by selective densification of substrate material or by the incorporation of high refractive index materials during deposition of a dielectric layer. Two dielectric thin films are deposited on top of the waveguide. The layer closest to the waveguide has a lower refractive index than the guiding layer to form a buffer layer. The second dielectric layer, or tuning layer, has a higher refractive index. The tuning and buffer layers allow optimization of the resonance wavelength, full-width half maximum of the resonance wavelength range and amplitude of the resonance. The tuning layer is coated with a thin metallic layer, to effect surface plasmon resonance, such as gold, silver, aluminum or one or more semiconducting materials.
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: February 25, 1997
    Assignee: American Research Corporation of Virginia
    Inventors: Howard P. Groger, Martin Weiss, Peter Lo, Bruce L. Thomas
  • Patent number: 5591407
    Abstract: A chemical sensor uses a semiconductor diode laser having a surface active region. A laser structure, including an active layer, a cladding layer, a barrier layer and a grating layer, is constructed on a substrate. A contact layer is deposited on a surface of the laser structure. One or more electrodes are positioned on the contact layer. A segmented electrode has a first contact pad, a second contact pad, and a surface active region between the first and second pads. A surface active region is created between the two electrodes. The tail of the lasing signal interacts with surface features of the diode laser or with chemical materials or probes in contact with the surface of the diode laser or in contact with coatings on the surface of the diode laser. Chemical changes in the ambient environment induce changes in the laser signal. The modified laser signal output is detected by a detector region integral with or separated from the laser structure.
    Type: Grant
    Filed: April 21, 1995
    Date of Patent: January 7, 1997
    Assignee: American Research Corporation of Virginia
    Inventors: Howard P. Groger, Peter Lo, Martin Weiss, Peter Zory
  • Patent number: 5577137
    Abstract: A fluorescent sensor for chemical analysis has a light source, an optical waveguide, and a detector. Fluorophores are associated with the optical waveguide. When an impervious waveguide is used, a fluorophore-containing layer is applied to a surface of the waveguide. The fluorophores are excited by a laser, a light emitting diode, an electroluminescent source or a lamp source emitting light propagating at angles to the waveguide. The light source is modulated. A mirror can be used to direct the light beam. The angle of light incidence on the waveguide can be altered by moving the waveguide itself. The waveguide traps the laser-induced fluorescence and projects fluorescence signals through a suitable filter to a photodetector or otherwise wavelength-specific photodetector positioned near the waveguide structure. Remote operation of the sensor is achieved using optical fibers. Patterned waveguides allow multiple excitation sources to illuminate multiple fluorescent probe materials.
    Type: Grant
    Filed: February 22, 1995
    Date of Patent: November 19, 1996
    Assignee: American Research Corporation of Virginia
    Inventors: Howard P. Groger, Peter Lo, Russell J. Churchill, Martin Weiss, Shufang Luo
  • Patent number: 5514337
    Abstract: An instrument is applied to the measurement of chemical species and concentration through the use of a chemically-sensitive coating on the eddy current coil or in the vicinity of the eddy current coil which produces a change in impedance of the probe through induced eddy currents in the coating. An eddy current or resonance circuit chemical detector is a non-contact sensor for measuring chemical species identity and concentration. The chemical detector is resilient and does not require reference electrodes. The chemical sensor is selective as a result of data available on the change in vector impedance of the probe, the change in resonant frequency of the tuned circuit, and the availability of data to construct a vector response from multiple probes having differing chemistries. The probe is used in extreme temperatures.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: May 7, 1996
    Assignee: American Research Corporation of Virginia
    Inventors: Howard P. Groger, Russell J. Churchill, James Kelsch
  • Patent number: 5427823
    Abstract: Alumino-silicate glass-ceramic coated carbon-carbon composite and graphitic substrates having resistance to oxidation and thermal cycling. The coatings are fabricated from plasma-sprayed powders of beta-spodumene, cordierite, beta-eucryptite or beta-quartz and are rapidly recrystallized by laser processing.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: June 27, 1995
    Assignee: American Research Corporation of Virginia
    Inventors: Usha Varshney, Howard P. Groger, Jesse J. Brown, Jr.
  • Patent number: 5415943
    Abstract: Wood composite materials containing veneer layers interposed with a thermoplastic adhesive containing a polyester such as polyethylene terephthalate and other thermoplastic polymer show increased impact resistance. The composite material may be manufactured using an adhesive transfer method or film extrusion.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: May 16, 1995
    Assignee: American Research Corporation of Virginia
    Inventors: Howard P. Groger, Frederick A. Kamke, Russell J. Churchill