Abstract: A micromechanical switch or relay in accordance with the invention includes a substrate, a source electrode, a gate electrode, a drain electrode, and various style beams. In one embodiment the beam is relatively long and includes flexures on at least one end, and has a small activation voltage.
Abstract: The present invention relates to microfabricated spectrometers including methods of making and using same. Microspectrometers can be formed in a single chip in which detectors and light sources can be monolithically integrated. The microspectrometer can be integrated into a sensor system to measure the optical and physical properties of solids and fluids.
Abstract: A process for forming polymer coatings on the surfaces of objects, e.g., medical stents, is disclosed. The coatings formed by the process of the invention comprise small spherical, spheroidal or irregular shape polymer particles, which may be adhered together. Coatings may have high porosity and high surface area.
Abstract: A method for the fabrication complex-transition metal oxide (CTMO)/semiconductor or dielectric substrate integrated devices includes the separation of the CTMO film growth process from the CTMO-film/semiconductor or dielectric substrate integration process. The CTMO-film is transferred from the native substrate to the final substrate for fabrication into devices. The CTMO-film is grown onto a native substrate under growth conditions chosen to provide a CTMO-film having desirable properties and thickness. No restrictions are placed upon the native substrate used, the growth method used, or on the growth conditions required. The CTMO-film is then joined to the semiconductor or dielectric substrate and the native substrate is removed, providing the basis for an integrated electronics, photonics, or MEMS device. Techniques fully compatible with semiconductor processing can be used to fabricate monolithically integrated CTMO/semiconductor devices in a first embodiment.
Type:
Grant
Filed:
March 13, 1997
Date of Patent:
September 5, 2000
Assignee:
Northeastern University
Inventors:
Steven A. Oliver, Paul Zavracky, Nicol E. McGruer, Carmine Vittoria
Abstract: A variable-coupling quasioptical electron paramagnetic resonance apparatus. In one embodiment, the variable-coupling quasioptical electron paramagnetic resonance apparatus includes a variable coupling quasioptical resonance cavity constructed from two back-to-back Fabry-Perot interferometers. One Fabry-Perot interferometer is formed from two partially reflecting mirrors. The second Fabry-Perot interferometer is an interferometer formed from one of the partially reflecting mirrors and a back mirror. A sample to be studied is placed within the cavity adjacent the partially reflecting mirrors and between one of the partially reflecting mirrors and the back mirror. The relative spacing of the partially reflecting mirrors and the back mirror is adjustable. With this arrangement, the interferometer can be made to act as a single mirror with variable reflectivity, thereby permitting incident radiation reaching the sample to be varied precisely and continuously.
Type:
Grant
Filed:
October 21, 1997
Date of Patent:
August 8, 2000
Assignee:
Northeastern University
Inventors:
David E. Budil, Keith A. Earle, Jack H. Freed, James R. Anderson
Abstract: The present invention is an active micromechanical electronic device of extremely small physical size, such that the device can take advantage of the quantum-mechanical phenomenon of electron tunneling. The device is produced using Scanning Electron Microscope (SEM) electron beam lithography. In operation, the gap between the tip of the beam and the drain contact is small enough (typically tens of angstroms) that electron tunneling occurs across the gap between the tip of the beam and the drain contact occurs, with the amount of resulting electron flow dependent on the width of the gap between the tip and the drain contact. The device acts as a controlled current source whose output is dependent on the mechanical position of the beam tip with respect to the drain contact. The tip to drain spacing varies due to the electrostatic force presented between the beam and the gate contact.
Abstract: Methods for detecting schizophrenia or depression based on modifications of the contribution of the D.sub.4 receptor to phospholipid methylation levels are described herein. Individuals with schizophrenia or depression have a deficiency in phospholipid methylation activity compared with normal individuals. Methods for screening therapeutic processes or agents for use in treatment of schizophrenia or related neuropsychiatric disorders are also described.
Abstract: A method of creating a diamond-like carbon film on a substrate, including the steps of exposing the substrate to a hydrocarbon gas environment and generating plasma in the environment of an electron density greater than approximately 5.times.10.sup.10 per cm.sup.3 and a sheath thickness less than about 2 mm under conditions of high ion flux and controlled, low energy ion bombardment.
Abstract: A subatmospheric, variable pressure sample delivery chamber, useful as an electrospray ionization device for introducing a sample into a mass spectrometer or as a sample delivery device for delivery of a sample to a collection device at subatmospheric pressures, is disclosed. The sample delivery chamber is configured to maintain an operating pressure between 1 and 750 Torr, preferably between 50 and 700 Torr. The chamber has an inlet port for introduction of a gas and an exit port capable of being coupled either to a sampling orifice for an analytical device, usually a mass spectrometer, or directly to a pump for removal of gas. A sample delivery device extends from outside the chamber into the interior of the chamber.
Type:
Grant
Filed:
January 17, 1997
Date of Patent:
May 30, 2000
Assignee:
Northeastern University
Inventors:
Barry L. Karger, Frantisek Foret, Daniel P. Kirby
Abstract: An underground object detector can locate and identify the shape of underground objects using a pulsed laser to generate acoustic waves in soil. A remotely located microphone detects an acoustic signal between the soil surface and subsurface objects. The amplitude of this acoustic signal is correlated with the position of the laser beam source and output on a visual display, resulting in an acoustic map of the ground. A raster scanning of the suspect ground in the vicinity reveals the shape of the underground object, allowing the operator to discriminate benign and natural objects.
Type:
Grant
Filed:
August 27, 1998
Date of Patent:
May 30, 2000
Assignee:
Northeastern University
Inventors:
Charles A. DiMarzio, Stephen W. McKnight, Scott C. Lindberg
Abstract: An auditory and tactile stimulation and feedback system for promoting development of individuals. The system stimulates attention and movement, helps individuals to learn cause and effect relationships, to control a surrounding environment and to promote normal development by facilitating the individual's exploration of a developmental sequence of sounds or other stimuli. The system includes an input device which can be interconnected electrically and physically with other input devices, all of which are responsive to the individual as the individual traverses the input devices.
Abstract: A system of gating orifices for continuous pressure infiltration processes eliminates blow-out of the pressurized molten metal matrix material and friction damage to the infiltrated perform. The system includes three or more orifices along a vertical path of an upwardly moving perform which passes from vacuum or atmospheric pressure into a pressurized infiltrating bath of molten metal, then into a pressurized atmosphere in which the matrix fully solidifies, and from there to an atmospheric environment. The entering orifice, at the bottom of the pressurized bath, is elongated in the direction of the perform movement to provide a temperature gradient from above the matrix material melting temperature at the bath to below the solidification temperature farthest from the bath. The resulting liquid-mushy-solid sequence of the matrix material forms a solidification seal to prevent blow out of the pressurized molten metal.
Abstract: A helical turbine assembly capable of providing high speed unidirectional rotation under a multidirectional ultra low-head fluid flow is disclosed. The assembly comprises an array of helical turbine units or modules arranged, vertically or horizontally, to harness, for example, water or wind power. Each turbine unit or module comprises a plurality of helical blades having an airfoil profile. The modules for wind power may be mounted to rotatable shafts supported by lightweight structures anchored by guy wires to the ground. The helical turbine can also a provide ship propulsion by utilizing the power of ocean waves. In a further embodiment, a cylindrical distributor is provided in the helical turbine to channel the fluid flow to the blades of the turbine, thereby increasing efficiency and power output. The helical turbine with distributor may be used to lift or lower a body either being submerged into a fast stream or dragged in the fluid.
Abstract: An optical quadrature interferometer is presented. The optical quadrature interferometer uses a different state of polarization in each of two arms of the interferometer. A light beam is split into two beams by a beamsplitter, each beam directed to a respective arm of the interferometer. In one arm, the measurement arm, the light beam is directed through a linear polarizer and a quarter wave plate to produce circularly polarized light, and then to a target being measured. In the other arm, the reference arm, the light beam is not subject to any change in polarization. After the light beams have traversed their respective arms, the light beams are combined by a recombining beamsplitter. As such, upon the beams of each arm being recombined, a polarizing element is used to separate the combined light beam into two separate fields which are in quadrature with each other.
Abstract: An apparatus and method for measuring instantaneous power using a magneto-optic Kerr effect sensor are disclosed. The apparatus comprises and the method requires a magneto-optic Kerr effect magnetic field sensing element and an optical system including a light source, first and second polarizers, and a photoconductive detector. In a preferred embodiment, the sensing element and the optical system are arranged to sense the intensity of a magnetic field generated by current passing through a high voltage power line so as to provide an optical signal that is representative of the current to the photoconductive detector. A voltage signal is tapped off of the high voltage power line to provide a bias signal to the photoconductive detector. The photoconductive detector thereby effectively multiplies the optical current signal with the voltage signal so as to provide a photoconductive detector current signal that is proportional to instantaneous power passing through the high voltage power line.
Type:
Grant
Filed:
October 10, 1997
Date of Patent:
November 30, 1999
Assignee:
Northeastern University
Inventors:
Charles A. DiMarzio, Steven A. Oliver, Stephen W. McKnight
Abstract: Methods of releasing and analyzing substrates such as DNA, comprising: a) covalently or ligandly binding substrate to a first electrode via a release group, which release group is cleavable in response to applied energy; b) introducing an electrical field so as to establish a charge potential between the first electrode and a second electrode separated by a vacuum or gas phase from the first electrode, the strength of such field sufficient to bristle said covalently-bound or ligandly-bound substrate; and c) applying sufficient energy directly to the release group to cleave the release group and release the substrate into a vacuum or gas phased
Abstract: A compiler which generates object-oriented code from high level models is disclosed. The compiler uses a class graph to construct a finite intermediate automaton which is used in conjunction with an adaptive program to generate an object-oriented program in a target language. The intermediate automaton enables general case compilation of most combinations of adaptive programs and class graphs. The automaton also enables use of standard minimization techniques which reduce the size of the generated object-oriented code.
Type:
Grant
Filed:
March 22, 1996
Date of Patent:
August 31, 1999
Assignee:
Northeastern University
Inventors:
Karl Lieberherr, Jens Palsberg, Boaz Patt-Shamir
Abstract: A monolithic inductively coupled plasma generator includes a first substrate having an electrical circuit disposed thereon which includes a substantially planar inductive coil, a capacitor electrically coupled in series with the coil, and a drive circuit electrically coupled to the coil for driving the circuit at resonance. The plasma generator further includes a plasma chamber proximate the coil in which a gas is excited.
Abstract: Drug-delivery devices and methods of their use are disclosed, which devices consist of at least a semi-interpenetrating network (semi-IPN) hydrogel comprising a first, cationic polymer such as chitosan and a second high molecular weight neutral polymer such as polyethylene oxide, the semi-IPN having been freeze-dried after formation of the semi-IPN, and a drug composition. A therapeutic method of treating gastric disease is also disclosed comprising the step(s) of introducing to a gastric area to be treated a drug-delivery device according to the disclosure, whereupon the device releases the drug or therapeutic agent contained in the device. The hydrogels of the disclosure are advantageously used for site-specific drug delivery in the gastro-intestinal tract where there is a range of pH from 1.0 to 1.5 in the stomach to about 7.5 in the small intestine.
Abstract: Articles of manufacture and methods of making the same, comprising a cationic polymer which has been surface-modified by a method comprising the steps of swelling a cationic polymer in a medium having a pH value <7; applying a surface-modifying agent to the cationic polymer to form a mixture; and adjusting the pH of the mixture to a value .gtoreq.7. A preferred embodiment relates to semipermeable membranes suitable for hemodialysis made from chitosan, the surface of which has been modified by anionic polysaccharides such as dextran or heparin, or anionic polyoxyalkylenes such as acid-modified polyethylene glycol, to improve blood compatibility.