A device for measuring pressure includes a curved microbeam having opposing ends, a length extending between the pair of opposing ends, and a plurality of resonant frequencies, an actuating electrode extending along the length of the curved microbeam and spaced from the curved microbeam, an AC power source in communication with one of the opposing ends and the actuating electrode to deliver an AC signal at a first symmetric resonant frequency and a second symmetric resonant frequency selected from the plurality of resonant frequencies to the curved microbeam, a DC power source in communication with the opposing ends to pass an electrothermal voltage along a length of the curved microbeam, and a frequency monitoring device to monitor changes in the first symmetric resonant frequency and the second symmetric resonant frequency caused by an ambient pressure surrounding the curved microbeam.

A resonant pressure sensor with improved linearity includes a substrate including a substrate-fixed portion fixed to a housing-fixed portion and a substrate-separated portion separated from the housing-fixed portion in a first direction; a first resonator disposed in the substrate-separated portion to detect a change of a resonance frequency based on a strain caused by static pressure applied by a pressure-receiving fluid interposed in a gap between the housing-fixed portion and the substrate; a first electrode extending along a second direction to output an excitation signal to the first resonator; a second electrode that extends along the second direction and from which the first resonator outputs a signal having the resonance frequency; and a processor that measures the static pressure based on the detected change.

A resonant pressure sensor with improved linearity includes: a substrate including a substrate-separated portion separated from a housing-fixed portion; a first resonator that: is disposed in the substrate-separated portion; and detects a change of a first resonance frequency based on a strain in the substrate caused by static pressure applied by a pressure-receiving fluid; a second resonator that: is disposed in the substrate; detects a change of a second resonance frequency based on the strain in the substrate; and has a pressure sensitivity of the second resonance frequency; and a processor that: measures the static pressure based on the detected change of the first resonance frequency; and corrects the static pressure according to internal temperature of the pressure sensor based on a difference between the second resonance frequency and the first resonance frequency.

A resonant pressure sensor includes: a housing; a housing-fixed portion that is fixed to the housing; a substrate that comprises: a substrate-fixed portion that is fixed to the housing-fixed portion; and a substrate-separated portion that is separated from the housing-fixed portion in a first direction and extends from the substrate-fixed portion; a first resonator that is disposed in the substrate-separated portion and that detects a change of a resonance frequency based on a strain in the substrate caused by static pressure applied by a pressure-receiving fluid; a first electrode that extends along a second direction perpendicular to the first direction and that outputs an excitation signal to the first resonator to excite the first resonator; and a second electrode that extends along the second direction and from which the first resonator outputs a signal having the resonance frequency.

A resonant pressure sensor has high linearity and includes: a housing; and a pressure sensing unit that detects a static pressure based on a change value of a resonance frequency and includes: a housing-fixed portion; a substrate that includes a substrate-fixed portion and a substrate-separated portion; the pressure-receiving fluid that is interposed in a gap between the housing-fixed portion and the substrate and envelops the substrate; and a first resonator that is disposed in the substrate-separated portion and detects the change value of the resonance frequency based on a strain in the substrate caused by the static pressure applied by the pressure-receiving fluid, wherein the first resonator is made of a semiconductor material including an impurity, a concentration of the impurity is 1×10.sup.20 (cm.sup.−3) or higher, and an atomic radius of the impurity is smaller than an atomic radius of the semiconductor material.

A device for measuring pressure includes a curved microbeam having opposing ends, a length extending between the pair of opposing ends, and a plurality of resonant frequencies, an actuating electrode extending along the length of the curved microbeam and spaced from the curved microbeam, an AC power source in communication with one of the opposing ends and the actuating electrode to deliver an AC signal at a first symmetric resonant frequency and a second symmetric resonant frequency selected from the plurality of resonant frequencies to the curved microbeam, a DC power source in communication with the opposing ends to pass an electrothermal voltage along a length of the curved microbeam, and a frequency monitoring device to monitor changes in the first symmetric resonant frequency and the second symmetric resonant frequency caused by an ambient pressure surrounding the curved microbeam.

A resonant pressure sensor with improved linearity includes: a substrate including a substrate-separated portion separated from a housing-fixed portion; a first resonator that: is disposed in the substrate-separated portion; and detects a change of a first resonance frequency based on a strain in the substrate caused by static pressure applied by a pressure-receiving fluid; a second resonator that: is disposed in the substrate; detects a change of a second resonance frequency based on the strain in the substrate; and has a pressure sensitivity of the second resonance frequency; and a processor that: measures the static pressure based on the detected change of the first resonance frequency; and corrects the static pressure according to internal temperature of the pressure sensor based on a difference between the second resonance frequency and the first resonance frequency.

An electromechanical pressure sensor includes an electromechanical resonator having a driving electrode, a sensing electrode, and a beam resonator arranged between the driving and sensing electrodes. The beam resonator includes a resonator beam coupled on a first end to a first fixed anchor and coupled on a second end to a fixed second fixed anchor. The electromechanical resonator also includes a first voltage source coupled to the driving electrode and configured to provide an alternating current to the driving electrode and a second voltage source coupled to the first fixed anchor. The second voltage source provides a DC bias to the resonator beam. The electromechanical resonator further includes a third voltage source coupled to the resonator beam via the first and second fixed anchors. The third voltage source is configured to supply a voltage to the resonator beam that results in a temperature differential between the resonator beam and the first and second fixed anchors. The electromechanical resonator also includes a processor coupled to the sensing electrode and configured to correlate a voltage on the sensing electrode with a pressure value.

A pressure gauge includes: an outer container defining an outer chamber set to a reference pressure (Pr); an inner container disposed in the outer container; and a tube setting the inside of a first inner chamber of the inner container to a measurement pressure (Px). The inner container includes: a cylindrical rigid wall portion; first and second pressure receiving plates that displace due to a differential pressure between the reference pressure and the measurement pressure; a bellows partitioning the inner container into the first inner chamber and a second inner chamber; and a pressure detection element disposed in the second inner chamber and detecting the measurement pressure based on the displacements of the first and the second pressure receiving plates. The outer chamber and the second inner chamber are set to the reference pressure of a high vacuum that is lower than a lower limit of the measurement pressure.

An electromechanical pressure sensor includes an electromechanical resonator having a driving electrode, a sensing electrode, and a beam resonator arranged between the driving and sensing electrodes. The beam resonator includes a resonator beam coupled on a first end to a first fixed anchor and coupled on a second end to a fixed second fixed anchor. The electromechanical resonator also includes a first voltage source coupled to the driving electrode and configured to provide an alternating current to the driving electrode and a second voltage source coupled to the first fixed anchor. The second voltage source provides a DC bias to the resonator beam. The electromechanical resonator further includes a third voltage source coupled to the resonator beam via the first and second fixed anchors. The third voltage source is configured to supply a voltage to the resonator beam that results in a temperature differential between the resonator beam and the first and second fixed anchors. The electromechanical resonator also includes a processor coupled to the sensing electrode and configured to correlate a voltage on the sensing electrode with a pressure value.