A 1D ultrasonic transducer unit for material detection, comprising a housing having securing device for securing to a surface and having at least three discrete ultrasonic transducers designed to decouple sound waves with a consistent operating frequency between 20 kHz and 400 kHz in a gaseous medium, and a control unit designed to control each ultrasonic transducer individually, wherein two ultrasonic transducers, directly adjacent to one another, are spaced apart by a distance, the 1D ultrasonic transducer unit has a sound channel per ultrasonic transducer with an input opening, associated with exactly one respective ultrasonic transducer, and an output opening, the output openings are arranged along a straight line, a distance from the directly adjacent output opening corresponds at most to the full or half the wavelength in the gaseous medium and is smaller than the corresponding distance.

Disclosed are devices, systems and methods for touch, force and/or thermal sensing by an ultrasonic transceiver chip. In some aspects, an ultrasonic transceiver sensor device includes a semiconductor substrate; a CMOS layer attached to the substrate; an array of piezoelectric transducers coupled to the CMOS layer to generate ultrasonic pulses; and a contact layer attached to the substrate on a side opposite the substrate for providing a surface for contact with an object, where an ultrasonic pulse generated by a piezoelectric transducer propagates through the substrate and the contact layer, such that when the object is in contact with the surface of the contact layer, a reflected ultrasonic pulse is produced and propagates through the contact layer and the substrate to be received at the array of piezoelectric transducers, and the CMOS layer receive and process outputs from the piezoelectric transducers produced in response to the received reflected ultrasonic pulses.

Disclosed are devices, systems and methods for touch, force and/or thermal sensing by an ultrasonic transceiver chip. In some aspects, an ultrasonic transceiver sensor device includes a semiconductor substrate; a CMOS layer attached to the substrate; an array of piezoelectric transducers coupled to the CMOS layer to generate ultrasonic pulses; and a contact layer attached to the substrate on a side opposite the substrate for providing a surface for contact with an object, where an ultrasonic pulse generated by a piezoelectric transducer propagates through the substrate and the contact layer, such that when the object is in contact with the surface of the contact layer, a reflected ultrasonic pulse is produced and propagates through the contact layer and the substrate to be received at the array of piezoelectric transducers, and the CMOS layer receive and process outputs from the piezoelectric transducers produced in response to the received reflected ultrasonic pulses.

Apparatuses and methods for measuring and characterizing ultrasound using thermoacoustic sensors are provided. Thermoacoustic sensors can include heat flux sensors for detecting a temperature difference (between the front and back of the heat flux sensor) and an absorber layer attached to the heat flux sensor for absorbing ultrasound, converting it to heat, and also acting as an acoustic impedance matching layer. An heat sink can also be used. In some embodiments, thermoacoustic sensors can be arranged into an acoustic integrating sphere and face inward to form a cavity. The sphere can have an opening to the cavity, wherein ultrasound emitted through the opening can cause a temperature difference that can be detected by the thermoacoustic sensors. These apparatuses and others can provide for methods of measuring ultrasound power and/or methods of determining an ultrasound profile as the angular distribution of emitted ultrasound power generated by an ultrasound transducer.

Apparatuses and methods for measuring and characterizing ultrasound using thermoacoustic sensors are provided. Thermoacoustic sensors can include heat flux sensors for detecting a temperature difference (between the front and back of the heat flux sensor) and an absorber layer attached to the heat flux sensor for absorbing ultrasound, converting it to heat, and also acting as an acoustic impedance matching layer. An heat sink can also be used. In some embodiments, thermoacoustic sensors can be arranged into an acoustic integrating sphere and face inward to form a cavity. The sphere can have an opening to the cavity, wherein ultrasound emitted through the opening can cause a temperature difference that can be detected by the thermoacoustic sensors. These apparatuses and others can provide for methods of measuring ultrasound power and/or methods of determining an ultrasound profile as the angular distribution of emitted ultrasound power generated by an ultrasound transducer.

A corrosion resistant coating suitable for use in harsh environments, such as for protecting a temperature probe for continuous use in the Hall-H?roult process can include at least one first layer comprising a metal boride and at least one second layer comprising a metal interposed between the substrate and the at least one metal boride layer. The coating can have a thickness of less than 10 micrometers.

A corrosion resistant coating suitable for use in harsh environments, such as for protecting a temperature probe for continuous use in the Hall-H?roult process can include at least one first layer comprising a metal boride and at least one second layer comprising a metal interposed between the substrate and the at least one metal boride layer. The coating can have a thickness of less than 10 micrometers.

A device includes: an ultrasonic wave irradiation unit that irradiates a living body with an ultrasonic wave; an ultrasonic wave detection unit that receives an ultrasonic wave reflected by the living body; and a calculation unit that calculates an amount of temperature change in the living body. The calculation unit is configured to: calculate a frequency of an ultrasonic wave amplified in the living body, based on information on a structure of the living body; perform frequency analysis on the ultrasonic wave received by the ultrasonic wave detection unit and acquire an amplitude spectrum of the ultrasonic wave; identify, from the amplitude spectrum, a peak frequency closest to the frequency of the ultrasonic wave; calculate an amount of frequency change, from two peak frequencies identified by ultrasonic wave irradiations in twice; and calculate an amount of temperature change in the living body from the amount of frequency change.

A device includes: an ultrasonic wave irradiation unit that irradiates a living body with an ultrasonic wave; an ultrasonic wave detection unit that receives an ultrasonic wave reflected by the living body; and a calculation unit that calculates an amount of temperature change in the living body. The calculation unit is configured to: calculate a frequency of an ultrasonic wave amplified in the living body, based on information on a structure of the living body; perform frequency analysis on the ultrasonic wave received by the ultrasonic wave detection unit and acquire an amplitude spectrum of the ultrasonic wave; identify, from the amplitude spectrum, a peak frequency closest to the frequency of the ultrasonic wave; calculate an amount of frequency change, from two peak frequencies identified by ultrasonic wave irradiations in twice; and calculate an amount of temperature change in the living body from the amount of frequency change.

In an embodiment, a sensor comprises a waveguide comprising a photoacoustic generation element disposed on the waveguide, the photoacoustic generation element comprising a photoabsorptive material; and a sensing element comprising an optical acoustic wave detector. In another embodiment, a sensing system comprises the sensor and a laser. In yet another embodiment, a method of sensing comprises providing the sensing system; heating the photoabsorptive material with a laser to generate an acoustic signal; sensing an intensity of laser light reflected by the optical acoustic wave detector to detect the acoustic signal; and determining a time of flight of the acoustic signal between the generation and the detection to determine a change in a parameter change in a medium between the photoabsorptive material and the optical acoustic wave detector.