Patents Assigned to Roxburgh Ltd.
  • Patent number: 6130464
    Abstract: A surface micromachined microaccelerometer includes a substrate which has a surface plane, and a cantilever formed on the substrate with a fixed end and a free end, the fixed end being anchored to the substrate. The cantilever includes a mass fixed along the length of the cantilever. A cooperating device reads out the occurrence of an acceleration event when the free end of the cantilever has moved to a predetermined position. The cooperating device may be fixed or an opposing co-aligned cantilever structure. In a first embodiment, the cooperating device takes the form of a fixed structure having slots in which the tip of the cantilever is selectively retained. A further embodiment configures the cooperating device as an overlapping opposed cantilever. A further feature of the invention enables a reset function of a latched cantilever and comprises a pair of layers which when energized cause a cantilever to be suitably deflected so as to return from the latched state back to the unlatched state.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: October 10, 2000
    Assignee: Roxburgh Ltd.
    Inventor: William N. Carr
  • Patent number: 5870007
    Abstract: A microstructure includes a substrate and a movable platform which is tethered by a first cantilever arm to the substrate. The first cantilever arm is comprised of a sandwich of first and second materials, the first and second materials exhibiting either different thermal coefficients of expansion or a piezoelectric layer. A second cantilever arm includes a first end which is tethered to the platform and a free distal end which is positioned to engage the substrate. The second cantilever arm is constructed similarly to the first cantilever arm. A controller enables movement of the platform through application of signals to both the first cantilever arm and the second cantilever arm to cause flexures of both thereof. The second cantilever arm, through engagement of its free end with the substrate, aids the action of the first cantilever arm in moving the platform.
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: February 9, 1999
    Assignee: Roxburgh Ltd.
    Inventors: William N. Carr, Xi-qing Sun
  • Patent number: 5796152
    Abstract: A cantilever microstructure includes a cantilever arm with a proximal end connected to a substrate and a freely movable distal end. The cantilever arm comprises first and second sections and includes a continuous layer which exhibits a first thermal co-efficient of expansion (TCE). In one embodiment, an electrical contact is positioned at the distal end of the cantilever arm. A first layer is positioned on a surface of the continuous layer and along the first section thereof. The first layer exhibits a second TCE which is different from the first TCE of the continuous layer. A second layer is positioned on a surface of the continuous layer and along the second section thereof. The second layer exhibits a third TCE which is different from the first TCE of the continuous layer. Electrical control circuitry selectively applies signals to the first and second layers to cause a heating thereof and a flexure of the cantilever arm so as to bring the distal end thereof into contact with a conductive substrate.
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: August 18, 1998
    Assignee: Roxburgh Ltd.
    Inventors: William N. Carr, Xi-qing Sun
  • Patent number: 5781331
    Abstract: An optical shutter apparatus includes a source of illumination and a first aperture plate positioned in a path of light from the source of illumination. A cantilever shutter is positioned at each aperture in the aperture plate and includes at least two bonded layers, one being an electrically resistive layer which exhibits a first thermal coefficient of expansion (TCE) and the second layer exhibiting a second TCE that is different from the first TCE. A proximal end of the bonded layers is attached to the aperture plate at each aperture and a distal portion thereof covers the respective aperture when in position thereover. A controller applies signals to the first electrically resistive layer to cause a heating of the first and second layers and a resultant unequal expansion thereof. The expansion causes a flexure of the cantilever shutter and moves the distal portion thereof to either cover or uncover the aperture, which, when uncovered, allows transmission of the illumination therethrough.
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: July 14, 1998
    Assignee: Roxburgh Ltd.
    Inventors: William N. Carr, Xi-qing Sun
  • Patent number: 5475318
    Abstract: A microprobe comprises a base, a microcantilever extending in a plane from the base, and a probe tip projecting from the microcantilever out of the plane. The microcantilever is a bimorph structure comprising first and second layers made from materials having different coefficients of thermal expansion, and an integrated heated element for supplying heat to the microcantilever. The probe tip is made from silicon and comes to a radius that can be controlled to atomic sharpness (<1 nm) if desired. Alternatively, the probe tip is a planar structure. Desirably, the microcantilever is made from a metal, such as aluminum, and silicon oxide as the materials of the two layers. The heating element comprises a line or ribbon of a conductive material, such as polysilicon which is in contact with one of the two layers, and supplies heat, thereby causing the probe tip to traverse an arc and bring it into contact with a material under investigation.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: December 12, 1995
    Assignees: Robert B. Marcus, Roxburgh Ltd.
    Inventors: Robert B. Marcus, William N. Carr