Abstract: Various exemplary embodiments relate to a device to measure carbon dioxide (CO2) levels, including a first oscillator group comprising a first sensor to measure air pressure, where the first sensor comprises a first sealed membrane, and where the first sealed membrane overlays a sealed first cavity; a second oscillator group including a second sensor to measure the resonance frequency of a second unsealed oscillating membrane, and where the second unsealed membrane overlays a second cavity in contact with the air outside of the second sensor; and a mixer accepting as input a first frequency measurement output from the first oscillator group and a second frequency measurement output from the second oscillator group, outputting the difference of the first frequency measurement and the second frequency measurement, and computing a carbon dioxide measurement based on the difference.

Abstract: One example discloses an acoustic pairing device, comprising: an acoustic processor configured to receive a first acoustic signal and a second acoustic signal; a signal comparison module configured to identify a propagation delay or amplitude difference between the first and second acoustic signals; and a pairing module configured to output a pairing signal if the propagation delay or amplitude difference is between a first value and a second value. Another example discloses a method for acoustic pairing between a first device and a second device, executed by a computer programmed with non-transient executable instructions, comprising: receiving a propagation delay or amplitude difference between a first acoustic signal and a second acoustic signal; pairing the first and second devices if the propagation delay or amplitude difference is between a first value and a second value.

Abstract: One example discloses an acoustic pairing device, comprising: an acoustic processor configured to receive a first acoustic signal and a second acoustic signal; a signal comparison module configured to identify a propagation delay or amplitude difference between the first and second acoustic signals; and a pairing module configured to output a pairing signal if the propagation delay or amplitude difference is between a first value and a second value. Another example discloses a method for acoustic pairing between a first device and a second device, executed by a computer programmed with non-transient executable instructions, comprising: receiving a propagation delay or amplitude difference between a first acoustic signal and a second acoustic signal; pairing the first and second devices if the propagation delay or amplitude difference is between a first value and a second value.

Abstract: Various exemplary embodiments relate to a pressure sensor including a pressure sensitive membrane suspended over a cavity, wherein the membrane is secured by a set of anchors to a substrate; and a getter material embedded in the membrane, wherein the surface of the getter is in contact with any gas within the cavity, and wherein two end points of the getter material are attached through the substrate by anchors capable of conducting through the substrate an electrical current through the getter material.

Abstract: Various exemplary embodiments relate to a magnetometer device to measure oscillation frequency, including a feedthrough loop including an amplifier and a voltage bias connected to a first input of a metallic membrane; a membrane ground connected to a membrane output; a fixed plate including a first fixed plate output connected to a second input of the amplifier, wherein the fixed plate is physically separated from the metallic membrane but connected to the metallic membrane by a Lorentz force, and where the physical separation differs due to an angle of a magnetic field relative to a direction of a current; a second fixed plate output sensitive to the Lorentz force; and a circuit connected to the second fixed plate output to calculate an angle of the magnetic force based upon the Lorentz force.

Abstract: One example discloses a MEMS device, including: a cavity having an internal environment; a seal isolating the internal environment from an external environment outside the MEMS device; wherein the seal is susceptible to damage in response to a calibration unsealing energy; wherein upon damage to the seal, a pathway forms which couples the internal environment to the external environment; and a calibration circuit capable of measuring the internal environment before and after damage to the seal.

Abstract: A method and apparatus for measuring the rate of flow of an ion-containing fluid in a channel are disclosed herein. The apparatus includes a captive sensor operable to detect changes in capacitance value due to the deflection of the ions in the fluid by a magnetic field, and a processor operable to determine a flow speed of fluid from the detected change in capacitance value and a predetermined value of magnetic field strength. Such apparatus may be implemented using CMOS technology. The apparatus may operate in a magnetic field generated by a permanent magnet and measure the flow reliably.

Abstract: Embodiments of a method for forming a suspended membrane include depositing a first electrically conductive material above a sacrificial layer and within a boundary trench. The first electrically conductive material forms a corner transition portion above the boundary trench. The method further includes removing a portion of the first electrically conductive material that removes at least a portion of uneven topography of the first electrically conductive material. The method further includes depositing a second electrically conductive material. The second electrically conductive material extends beyond the boundary trench. The method further includes removing the sacrificial layer through etch openings and forming a cavity below the second electrically conductive material. The first electrically conductive material defines a portion of a sidewall boundary of the cavity.

Abstract: In an embodiment, a method for calibrating a pressure sensor device is disclosed. The method involves determining the resonant frequency of a membrane of the pressure sensor device after the pressure sensor device has been attached to a circuit board, calculating a change in the resonant frequency from a resonant frequency stored in memory, calculating strain of the membrane of the pressure sensor device from the change in resonant frequency, and calibrating the pressure sensor device based on a capacitance-to-pressure curve calculated using the strain of the membrane of the pressure sensor device.

Abstract: A resonator has a main resonator body and a secondary resonator structure. The resonator body has a desired mode of vibration of the resonator alone, and a parasitic mode of vibration, wherein the parasitic mode comprises vibration of the resonator body and the secondary resonator structure as a composite body. In this way, unwanted vibrational modes are quenched by the second suspended body.

Abstract: Various exemplary embodiments relate to a device to measure carbon dioxide (CO2) levels, including a first oscillator group comprising a first sensor to measure air pressure, where the first sensor comprises a first sealed membrane, and where the first sealed membrane overlays a sealed first cavity; a second oscillator group including a second sensor to measure the resonance frequency of a second unsealed oscillating membrane, and where the second unsealed membrane overlays a second cavity in contact with the air outside of the second sensor; and a mixer accepting as input a first frequency measurement output from the first oscillator group and a second frequency measurement output from the second oscillator group, outputting the difference of the first frequency measurement and the second frequency measurement, and computing a carbon dioxide measurement based on the difference.

Abstract: Various exemplary embodiments relate to a magnetometer device to measure oscillation frequency, including a feedthrough loop including an amplifier and a voltage bias connected to a first input of a metallic membrane; a membrane ground connected to a membrane output; a fixed plate including a first fixed plate output connected to a second input of the amplifier, wherein the fixed plate is physically separated from the metallic membrane but connected to the metallic membrane by a Lorentz force, and where the physical separation differs due to an angle of a magnetic field relative to a direction of a current; a second fixed plate output sensitive to the Lorentz force; and a circuit connected to the second fixed plate output to calculate an angle of the magnetic force based upon the Lorentz force.

Abstract: Consistent with an example embodiment, a user (touch screen) interface has haptic feedback. The user interface comprises, a substrate, a transparent bottom electrode on top of the substrate, a transparent wrinkling layer on top of the transparent bottom electrode, a transparent top electrode on top of the transparent wrinkling layer; and a transparent protective surface on top of the transparent top electrode. The transparent wrinkling layer changes from a smooth surface to a roughened surface upon application of a voltage between the top electrode and the bottom electrode; the voltage generates an electrostatic force mutually attracting the top and bottom electrodes to exert a compressive force upon the transparent wrinkling layer sufficient to generate a degree of surface wrinkling that is perceptible to the touch.

Abstract: Various exemplary embodiments relate to a pressure sensor including a pressure sensitive membrane suspended over a cavity, wherein the membrane is secured by a set of anchors to a substrate; and a getter material embedded in the membrane, wherein the surface of the getter is in contact with any gas within the cavity, and wherein two end points of the getter material are attached through the substrate by anchors capable of conducting through the substrate an electrical current through the getter material.

Abstract: Embodiments of a method for forming a suspended membrane include depositing a first electrically conductive material above a sacrificial layer and within a boundary trench. The first electrically conductive material forms a corner transition portion above the boundary trench. The method further includes removing a portion of the first electrically conductive material that removes at least a portion of uneven topography of the first electrically conductive material. The method further includes depositing a second electrically conductive material. The second electrically conductive material extends beyond the boundary trench. The method further includes removing the sacrificial layer through etch openings and forming a cavity below the second electrically conductive material. The first electrically conductive material defines a portion of a sidewall boundary of the cavity.

Abstract: One example discloses a MEMS device, including: a cavity having an internal environment; a seal isolating the internal environment from an external environment outside the MEMS device; wherein the seal is susceptible to damage in response to a calibration unsealing energy; wherein upon damage to the seal, a pathway forms which couples the internal environment to the external environment; and a calibration circuit capable of measuring the internal environment before and after damage to the seal.

Abstract: Flow sensors for measuring the flow of an ion-containing fluid may be implemented using mechanical or electrical techniques. Mechanical flow sensors are have moving parts and therefore may be unreliable after some time and are expensive to manufacture. Hall-effect type flow sensors typically require a reversible magnetic field to compensate for electrochemical effects. A flow meter including such a sensor uses an electromagnet. A flow sensor (100) is described using a capacitive sensor (10) and processor (12) to determine the flow rate from a change in capacitance and a magnetic field. Such a flow sensor may be implemented using CMOS technology. The flow sensor may operate in a magnetic field generated by a permanent magnet and measure the flow reliably.

Abstract: A resonator comprising a resonator body and actuation electrodes for driving the resonator into a resonant mode, in which the resonator body vibrates parallel to a first axis. The resonator comprises means to apply a voltage to the resonator in a direction perpendicular to the first axis direction. This serves to shift the frequency of resonant modes other than the principal resonant mode, and this allows increased amplitude of output signal from the resonator.

Abstract: A resonator in which in addition to the normal anchor at a nodal point, a second anchor arrangement is provided and an associated connecting arm between the resonator body and the second anchor arrangement. The connecting arm connects to the resonator body at a non-nodal point so that it is not connected to a normal position where fixed connections are made. The connecting arm is used to suppress transverse modes of vibration.

Abstract: A resonator has a main resonator body and a secondary resonator structure. The resonator body has a desired mode of vibration of the resonator alone, and a parasitic mode of vibration, wherein the parasitic mode comprises vibration of the resonator body and the secondary resonator structure as a composite body. In this way, unwanted vibrational modes are quenched by the second suspended body.