A sensor device (1) comprises a piezoelectric transducer (3) and a base member (2). The piezoelectric transducer includes a piezoelectric member with at least one excitation electrode (37, 38) connected to a first face thereof and having a thickness (h) between the first face and a second face. The piezoelectric transducer (3) is attached to a supporting face of the base member (2) with the second face of the piezoelectric transducer positioned adjacent the supporting face of the base member. The base member includes at least one acoustic wave reflecting tag (21) distant from the piezoelectric member.

The present disclosure provides a new and improved temperature compensated surface-launched acoustic wave (SAW) strain sensor using multiple reflectors in SAW devices mounted on a split-carrier package that provides complete isolation from strain for a temperature sensing portion of the device, while exposing a strain sensing portion of the device to both strain and temperature, with the influence of temperature being common to the various portions of the device, and a single acoustic reference with respect to which multiple differential acoustic measurements can be made, to provide inherently temperature-compensated strain measurements.

An acoustic wave pressure sensor device configured to measure a pressure, comprising a substrate configured to bend when pressure is applied to the substrate such that an area of a first kind of strain and an area of a second kind of strain are formed in the substrate; an interdigitated transducer formed over the substrate; a first Bragg mirror formed over the substrate and arranged on one side of the interdigitated transducer; a second Bragg mirror formed over the substrate and arranged on another side of the interdigitated transducer; a first resonance cavity formed between the interdigitated transducer and the first Bragg mirror; a second resonance cavity formed between the interdigitated transducer and the second Bragg mirror; and wherein the first resonance cavity is formed over the area of the first kind of strain and the second resonance cavity is formed over the area of the second kind of strain.

Disclosed in the present disclosure are a surface-acoustic-wave temperature and pressure sensing device and a manufacturing method thereof. The surface-acoustic-wave temperature and pressure sensing device includes a first high-temperature-resistant substrate and a second high-temperature-resistant substrate bonded together, where a recess is formed in the second high-temperature-resistant substrate to form a sealed cavity between the first high-temperature-resistant substrate and the second high-temperature-resistant substrate; first surface-acoustic-wave temperature sensors and surface-acoustic-wave pressure sensors are formed on a first surface of the first high-temperature-resistant substrate located in the cavity, and second surface-acoustic-wave temperature sensors are formed on a second surface of the first high-temperature-resistant substrate opposite the first surface; and the first surface-acoustic-wave temperature sensors, the second surface-acoustic-wave temperature sensors, and the surface-acoustic-wave pressure sensors are electrically connected to one another.

An acoustic wave device fabrication method includes: forming on a piezoelectric substrate a comb-shaped electrode and a wiring layer coupled to the comb-shaped electrode; forming on the piezoelectric substrate a first dielectric film having a film thickness greater than those of the comb-shaped electrode and the wiring layer, covering the comb-shaped electrode and the wiring layer, and being made of silicon oxide doped with an element or undoped silicon oxide; forming on the first dielectric film a second dielectric film having an aperture above the wiring layer; removing the first dielectric film exposed by the aperture of the second dielectric film by wet etching using an etching liquid causing an etching rate of the second dielectric film to be less than that of the first dielectric film so that the first dielectric film is left so as to cover an end face of the wiring layer and the comb-shaped electrode.

An output shaft of a transmission is fixed to a planetary gearset carrier. Output torque is measured via a surface acoustic wave sensor affixed to a face of the carrier between two adjacent planet gears and radially inside a weld joining the carrier face to an opposite carrier face. In this location, the level of strain at typical transmission output torques produces a level of strain within the measuring range of a surface acoustic wave sensor. The sensor may be powered and signals communicated across an air gap defined by signal rings. Due the stable position and orientation of the carrier, a small, consistent air gap is possible.

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.

Technologies for a fabric acoustic sensor are disclosed. The fabric acoustic sensor includes a conductive thread and a non-conductive thread, which form a diaphragm that vibrates in response to a sound wave. As a result of the vibration, the conductive thread stretches, and a resistance of the conductive thread varies. The change in resistance is measured by a compute device, and the compute device may determine the sound wave based on the change in resistance. In some embodiments, the fabric acoustic sensor may be used to monitor a heart rate, locate an object, and/or provide an input for noise cancellation.

An acoustic disdrometer is provided for measuring precipitation. The acoustic disdrometer has an acoustic transducer positioned within an acoustic chamber defined by an acoustic shell. Precipitation impacting the acoustic shell generates sound waves that are collected by the acoustic transducer for processing.

A measurement transducer for simultaneously measuring a force that can be both dynamic and static includes at least one piezoelectric transducer element having element surfaces on which the force generates electrical polarization charges proportional to a magnitude of the force. The measurement transducer includes a resonator element which can be excited to at least one resonance frequency and undergoes a transverse expansion from the action of the force in a transverse direction to the force. The magnitude of the transverse expansion is proportional to the magnitude of the force and causes in the resonance frequency a change that is a function of the force.