Abstract:
A strain sensor device for measuring loads on aircraft landing gear. This is done by measuring strains in the lower end of the strut, by which we infer the loading in the entire landing gear structure. These strains can be very large (as high as 10,000 microstrain) and can be imposed in numerous random directions and levels. The present invention includes a removable sensor assembly. An electromechanical means is presented that can accommodate large strains, be firmly attached to the strut, and provide good accuracy and resolution.
Abstract:
A method for making a pressure sensor including the steps of providing a substrate and forming or locating a pressure sensing component on the substrate. The method further includes the step of, after the forming or locating step, etching a cavity in the substrate below the pressure sensing component to define a diaphragm above the cavity with the pressure sensing component located on the diaphragm. The pressure sensing component includes an electrically conductive electron gas which changes its electrical resistance thereacross upon movement of the diaphragm.
Abstract:
Disclosed are capacitive pressure probes or sensors for high temperature applications. The capacitive pressure sensors of the present invention include, inter alia, a sapphire diaphragm which is disposed within an interior sensing chamber of the probe housing and has a first electrode formed on a central portion thereof. The central portion of the diaphragm and the first electrode are adapted and configured to deflect in response to pressure variations encountered within an interior sensing chamber and by the pressure sensor. A sapphire substrate which has a second electrode formed thereon is fused to the sapphire diaphragm about its periphery to form a sapphire stack and to define a reference chamber therebetween. Prior to fusing the sapphire diaphragm to the sapphire substrate, all contact surfaces are chemically treated and prepared using plasma activation, so as to create a bonding layer and to reduce the temperature required for the fusion.
Abstract:
A process for fabricating a pendulous accelerometer, including the steps of: providing a first substrate having a top planar surface, etching a portion of the first substrate to a first predetermined depth from the top planar surface to form a plurality of first protrusions, providing a second substrate, etching a portion of the second substrate to a second predetermined depth to form a plurality of second protrusions, bonding planar surfaces of the first protrusions to planar surfaces of the second protrusions, and etching a portion of the first substrate from an opposite side of the first substrate to a third predetermined depth equal to or greater than the difference between the total thickness of the first substrate and the first predetermined depth to form a freely rotatable sensing plate that includes a substantially hollow proof mass.
Abstract:
A micro mirror array including an upper wafer portion having a plurality of movable reflective surfaces located thereon, the upper wafer portion defining a coverage area in top view. The array further includes a lower wafer portion located generally below and coupled to the upper wafer portion. The lower wafer portion includes at least one connection site located thereon, the at least one connection site being electrically or operatively coupled to at least one component which can control the movement of at least one of the reflective surfaces. The at least one connection site is not generally located within the coverage area of the upper wafer portion.
Abstract:
A micro mirror structure including a plurality of individually movable mirrors. Each mirror has a generally concave shape from a top perspective at a temperature of about 20 degrees Celsius and has a generally convex shape from a top perspective at a temperature of about 85 degrees Celsius. In one embodiment, the radius of curvature may be greater than about 500 mm at a temperature of about 20 degrees Celsius and may be less than about −600 mm at a temperature of about 85 degrees Celsius at a thickness of about 10 microns. In another embodiment, the invention is a micro mirror structure including a plurality of individually movable mirrors arranged in an array. Each mirror includes a substrate, a diffusion barrier layer located above the substrate, and a reflective layer located above the diffusion barrier layer. The diffusion barrier layer generally limits the diffusion of the top reflective layer through the diffusion barrier layer.
Abstract:
The present invention relates to a micromachined hemispherical resonance gyroscope, which comprises a resonant layer, said resonant layer comprising a hemispherical shell which has a concave inner surface and an outer surface opposite to the inner surface, and top point of the hemispherical shell being its anchor point; several silicon hemispherical electrodes being arranged around said hemispherical shell, the silicon hemispherical electrodes including driving electrodes, equilibrium electrodes, signal detection electrodes and shielded electrodes, the shielded electrodes separating the driving electrodes and the equilibrium electrodes from the signal detection electrodes, the hemispherical shell and the several silicon spherical electrodes which surround the hemispherical shell constituting several capacitors; the resonant layer being made of polysilicon or silica or silicon oxide or diamond. The hemispherical resonance micromechanical gyroscope utilizes a processing method on the basis of silicon micromachining, which leads to small size and low production cost, as well as batch production capacity, meanwhile its sensitivity is independent of amplitude and its driving voltage could be very low, as a result its output noise could be significantly reduced, and its accuracy is better than the gyroscope products in the prior art.
Abstract:
A system for determining in-plane acceleration of an object. The system includes an in-plane accelerometer with a substrate rigidly attached to an object, and a proof mass—formed from a single piece of material—movably positioned a predetermined distance above the substrate. The proof mass includes a plurality of electrode protrusions extending downward from the proof mass to form a gap of varying height between the proof mass and the substrate. The proof mass is configured to move in a direction parallel to the upper surfaces of each of the plurality of substrate electrodes when the object is accelerating, which results in a change in the area of the gap, and a change in capacitance between the substrate and the proof mass. The in-plane accelerometer can be fabricated using the same techniques used to fabricate an out-of-plane accelerometer and is suitable for high-shock applications.
Abstract:
A system for determining in-plane acceleration of an object. The system includes an in-plane accelerometer with a substrate rigidly attached to an object, and a proof mass—formed from a single piece of material—movably positioned a predetermined distance above the substrate. The proof mass includes a plurality of electrode protrusions extending downward from the proof mass to form a gap of varying height between the proof mass and the substrate. The proof mass is configured to move in a direction parallel to the upper surfaces of each of the plurality of substrate electrodes when the object is accelerating, which results in a change in the area of the gap, and a change in capacitance between the substrate and the proof mass. The in-plane accelerometer can be fabricated using the same techniques used to fabricate an out-of-plane accelerometer and is suitable for high-shock applications.
Abstract:
A pendulous capacitive accelerometer including a substrate having a substantially planar upper surface with an electrode section, and a sensing plate having a central anchor portion supported on the upper surface of the substrate to define a hinge axis. The sensing plate includes a solid proof mass on a first side of the central anchor portion and a substantially hollow proof mass on a second side of the central anchor portion, providing for reduced overall chip size and balanced gas damping. The solid proof mass has a first lower surface with a first electrode element thereon, and the substantially hollow proof mass has a second lower surface with a second electrode element thereon. Both the solid proof mass and the hollow proof mass have the same capacitive sensing area. The sensing plate rotates about the hinge axis relative to the upper surface of the substrate in response to an acceleration.