In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor located in an opening defined by a body of the proof mass, a spring, a drive electrode, and a sense beam. The spring and the proof mass form a spring system suspended from the anchor. The sense beam oscillates at a particular resonance frequency based on application of a signal to the drive electrode. The MEMS device further includes a support structure coupled to the anchor. The support structure operates as a stress decoupling area and includes a support beam, with the spring corresponding to an end of the support beam that has a reduced thickness. The sense beam has a first end attached to the proof mass and a second end attached to the support beam such that the sense beam is orthogonal to the support beam.

A SAW-based inertial sensor incorporates a curved SAW drive resonator and graphene electrodes to increase the Coriolis force on a pillar array and generate secondary SAW waves that create a strain-induced hyperfine frequency transition in an enclosed alkali atom vapor, in conjunction with an integrated FP resonator to measure very small inertial signals corresponding to 10 μg and 0.01°/hr, representing a dynamic range of 10 orders of magnitude.

Disclosure of a novel accelerometer sensor method for detecting and measuring acceleration using paired radio frequency (RF) quartz crystal oscillators (QCO). Quartz crystal oscillators/resonators are known to be sensitive to acceleration or force impact events. Force impact events cause fluctuations in the quartz crystal resonator's natural resonant frequency. Normally this sensitivity to acceleration in QCOs is viewed as a negative property to be mitigated. This innovation exploits it in order to make a solid-state accelerometer with no mechanical parts. The crystalline structure of quartz crystal also has a preferred direction of maximum sensitivity to acceleration. There exists a mathematical relationship which relates these fluctuations in the resonator's natural frequency to the magnitude and direction of the accelerating source. Pairing acceleration sensitive QCO resonators will increase this sensor's sensitivity to acceleration. This will improve the measurement resolution for tracking changes in the QCO's frequency to determine the magnitude and direction of acceleration over time.

Described herein are accelerometers, apparatus and systems incorporating accelerometers, and techniques for controlling sensing operations in an accelerometer. In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor, a spring between the proof mass and the anchor, a drive electrode, and a sense beam. The anchor is located in an opening defined by a body of the proof mass. The spring and the proof mass form a spring system suspended from the anchor. The sense beam is configured to oscillate at a particular resonance frequency that changes according to a force generated by movement of the proof mass in response to acceleration. In some embodiments, a support structure couples the anchor to the spring and operates as a stress decoupling area that prevents or limits propagation of stress from the anchor to the sense beam and the spring system.

A resonant sensor device includes a base and a detection substrate. The detection substrate includes a movable portion configured to move in a first direction, a supporter includes one or more supporting portions which extend in a direction along an intersecting plane intersecting the first direction, an intermediate fixing portion which is connected to the movable portion via the supporter, a connection portion which connects a mounting portion fixed to the base to the intermediate fixing portion in a second direction that is one direction along the intersecting plane, and a resonator at least partially embedded in the one or more supporting portions. The maximum dimension of the connection portion in a third direction orthogonal to the second direction in the intersecting plane is smaller than a maximum dimension of the supporter in the third direction.

A SAW-based inertial sensor incorporates a curved SAW drive resonator and graphene electrodes to increase the Coriolis force on a pillar array and generate secondary SAW waves that create a strain-induced hyperfine frequency transition in an enclosed alkali atom vapor, in conjunction with an integrated FP resonator to measure very small inertial signals corresponding to 10 g and 0.01/hr, representing a dynamic range of 10 orders of magnitude.

A resonant sensor device includes a base and a detection substrate. The detection substrate includes a movable portion configured to move in a first direction, a supporter includes one or more supporting portions which extend in a direction along an intersecting plane intersecting the first direction, an intermediate fixing portion which is connected to the movable portion via the supporter, a connection portion which connects a mounting portion fixed to the base to the intermediate fixing portion in a second direction that is one direction along the intersecting plane, and a resonator at least partially embedded in the one or more supporting portions. The maximum dimension of the connection portion in a third direction orthogonal to the second direction in the intersecting plane is smaller than a maximum dimension of the supporter in the third direction.

Disclosure of a novel accelerometer sensor method for detecting and measuring acceleration using radio frequency (RF) oscillators. Quartz crystal oscillators (QCO) and surface acoustic wave (SAW) oscillators are known to be sensitive to acceleration or force impact events. These events cause fluctuations in the quartz crystal oscillator base natural resonant frequency. The crystalline structure of quartz crystal has a preferred direction of maximum sensitivity to acceleration. Acceleration or sudden force impact events cause fluctuations in the resonant frequency of quartz crystal and surface acoustic wave oscillators, increasing jitter and phase noise. There exists a mathematical relationship which relates these fluctuations in the natural frequency to the magnitude and direction of the accelerating source. This acceleration sensitivity can therefore be utilized to track changes in the oscillator resonant frequency referred to as jitter or phase noise to determine the magnitude of acceleration over time.

In some embodiments, a micro electro mechanical system (MEMS) includes a proof mass, sense electrodes, sense circuitry, and a frequency matching circuitry. The proof mass is configured to move responsive to stimuli. The sense electrodes are configured to generate a signal responsive to the proof mass moving. The sense circuitry is coupled to the sense electrodes. The sense circuitry is configured to receive the generated signal and further configured to process the generated signal. The frequency matching circuitry is configured to apply a DC voltage to the sense electrodes. The DC voltage is configured to change a stiffness of a spring of the proof mass. According to some embodiments, the change in the stiffness of the spring matches a resonance frequency between a sense mode and a drive mode. According to some embodiments, the sense electrodes are a comb structure.

A micro-electromechanical system (1) comprising: a sensor device (2), with a measuring deformer (3) exhibiting an effective temperature T1; a high-frequency resonator (4) that is mechanically coupled to the sensor device (2) and can interact with the measuring deformer (3); an energy converter (7) that is operatively connected to the high-frequency resonator (4) and is configured to excite the high-frequency resonator (4) into a vibration state, wherein, through the interaction of the vibrating high-frequency resonator (4) with the measuring deformer (3), energy can be transferred from the measuring deformer (3) to the high-frequency resonator (4) in such a manner that the measuring deformer (3) after the energy transfer exhibits an effective temperature T2 lower than T1.