Abstract: Angular rate sensors cause a stream of fluid to flow by heating the fluid. A trajectory of the stream of fluid is deflected by Coriolis forces. Apparatus according to some embodiments provides two heaters spaced apart along a channel. A stream of gas can be made to flow along the channel by operating one of the heaters. The flow can be periodically reversed by alternating operation of the heaters. Temperature sensors may be applied to detect deflection of the flowing gas. Angular rate sensors may be fabricated inexpensively by micromachining techniques.

Abstract: Microstructures can be formed as patterned layers on a substrate and then erecting the microstructures out of the plane of the substrate. The microstructures may be formed over circuits in the substrate. In some embodiments the patterned layer provides resiliently-flexible members such as cantilevers or springs that can be buckled to permit an edge defined by the patterned layer to engage a surface of the substrate. In some embodiments deformation of the resiliently-flexible members results the edge being forced against the substrate. Such microstructures may be applied in a wide range of applications including supporting optical elements, sensors, antennas or the like out of the plane of a substrate. Examples of accelerometer structures are described.

Abstract: Angular rate sensors cause a stream of fluid to flow by heating the fluid. A trajectory of the stream of fluid is deflected by Coriolis forces. Apparatus according to some embodiments provides two heaters spaced apart along a channel. A stream of gas can be made to flow along the channel by operating one of the heaters. The flow can be periodically reversed by alternating operation of the heaters. Temperature sensors may be applied to detect deflection of the flowing gas. Angular rate sensors may be fabricated inexpensively by micromachining techniques.

Abstract: Microstructures can be formed as patterned layers on a substrate and then erecting the microstructures out of the plane of the substrate. The microstructures may be formed over circuits in the substrate. In some embodiments the patterned layer provides resiliently-flexible members such as cantilevers or springs that can be buckled to permit an edge defined by the patterned layer to engage a surface of the substrate. In some embodiments deformation of the resiliently-flexible members results the edge being forced against the substrate. Such microstructures may be applied in a wide range of applications including supporting optical elements, sensors, antennas or the like out of the plane of a substrate. Examples of accelerometer structures are described.

Abstract: A thermal pressure sensor monitors pressure by measuring effects caused by variations of thermal conductivity between a member and a substrate to which the member is adhered by stiction. The interface between the member and the substrate behaves as an extremely narrow gap. In a preferred embodiment the member is a bridge extending between a pair of cantilever arms. Two pressure sensors may be combined in a Wheatstone bridge configuration. A method for fabricating a pressure sensor according to the invention comprises forming a layer of oxide on a substrate, depositing a layer of material on the oxide layer, forming the member from the layer of material, removing the oxide layer and then bringing the member into contact with the substrate. The portion of the substrate under the member may be patterned with plateaus and valleys.

Abstract: An integrated convective accelerometer device. The device includes a thermal acceleration sensor having a thermopile and a heater element; control circuitry for providing closed-loop control of the thermopile common-mode voltage; an instrumentation amplifier; clock generation circuitry; voltage reference circuitry; a temperature sensor; and, output amplifiers. The device can be operated in an absolute or ratiometric mode. Further, the device is formed in a silicon substrate using standard semiconductor processes and is packaged in a standard integrated circuit package.

Abstract: An accelerometer has a substrate with a cavity therein, a heater extending over the cavity, and a pair of temperature sensitive elements each spaced apart from the heater a distance of 75-400 microns also extending over the cavity. On passing an electrical current through the heater a symmetrical temperature distribution is set up on both sides of the heater. On acceleration, this distribution moves and by measuring the temperature as sensed by the pair of temperature sensitive elements the acceleration that caused the shift can be calculated.

Abstract: A process for fabricating an accelerometer, which includes providing a substrate with a layer of electrically conductive material on the substrate, micromachining the substrate to form a central electrical heater, a pair of temperature sensitive elements, and a cavity beneath the heater and the temperature sensing elements. Each temperature sensing element is spaced apart from said heater a distance in the range of 75 to 400 microns. The temperature sensing elements are located on opposite sides of the heater, thereby forming an accelerometer.

Abstract: A process for fabricating an accelerometer, which includes providing a substrate with a layer of electrically conductive material on the substrate, micromachining the substrate to form a central electrical heater, a pair of temperature sensitive elements, and a cavity beneath the heater and the temperature sensing elements. Each temperature sensing element is spaced apart from said heater a distance in the range of 75 to 400 microns. The temperature sensing elements are located on opposite sides of the heater, thereby forming an accelerometer.

Abstract: An accelerometer has a substrate with a cavity therein, a heater extending over the cavity, and a pair of temperature sensitive elements each spaced apart from the heater a distance of 75-400 microns also extending over the cavity. On passing an electrical current through the heater a symmetrical temperature distribution is set up on both sides of the heater. On acceleration, this distribution moves and by measuring the temperature as sensed by the pair of temperature sensitive elements the acceleration that caused the shift can be calculated.

Abstract: A thermal pressure sensor monitors pressure by measuring effects caused by variations of thermal conductivity between a member and a substrate to which the member is adhered by stiction. The interface between the member and the substrate behaves as an extremely narrow gap. In a preferred embodiment the member is a bridge extending between a pair of cantilever arms. Two pressure sensors may be combined in a Wheatstone bridge configuration. A method for fabricating a pressure sensor according to the invention comprises forming a layer of oxide on a substrate, depositing a layer of material on the oxide layer, forming the member from the layer of material, removing the oxide layer and then bringing the member into contact with the substrate. The portion of the substrate under the member may be patterned with plateaus and valleys.

Abstract: An accelerometer having a substrate with a cavity therein, a heater extending over the cavity, a pair of temperature sensitive elements extending over the cavity equidistant from the heater, and an electrical conductor couplable to an external power source and operative to pass electrical current through the heater so as to develop a symmetrical temperature gradient in the fluid extending outwardly from the heater to the two temperature sensors. The fluid may be a liquid or a gas surrounding the heater and temperature sensors. Applied acceleration disturbs this symmetry and produces a differential temperature between the two temperature sensors proportional to the acceleration.

Abstract: Joystick controller apparatus in which a pair of joystick controllers may send signal bursts on the same communication channel in the infrared frequency range by means of an electromagnetic transmission without recognizable loss of data. An error checking system is also provided to eliminate the effects of noise. A universal cable connector is provided for connection to various video game apparatus.

Abstract: An implantable intracranial pressure (ICP) telemetry transmitter. Data transmission is accomplished by means of a radio frequency (RF) link coupled to a silicon piezoresistive pressure transducer. Electrostatic bonding of this transducer onto a tubular glass support provides long-term stability, stress isolation and a hermetic package. Because of the large temperature coefficient of the electrostatically bonded pressure transducer (-6 to -9 mm Hg/.degree.C.), a temperature sensor is added to allow temperature compensation to be carried out. Pulse code modulation is employed to assure accurate data transmission. Use of low duty cycle pulse powering techniques lowers the power consumption of the telemeter. The complexity of the electronics is reduced by the use of a custom integrated circuit. Two lithium batteries can provide more than one month of continuous operation and an RF command receiver provides ON/Off control of the telemeter to extend the lifetime of the telemeter.