A transducer assembly operable to transmit ultrasonic energy in a desired direction towards a zone adapted to be acoustically coupled to an object or area of interest, the assembly comprising: a transducer layer; a backing material disposed behind said transduction material with respect to the desired direction; a back-matching layer disposed between the transducer layer and the backing material to reflect towards said transducer layer part of the ultrasonic energy directed from the transducer layer to the backing material.

The backing layer has an acoustic impedance higher than the acoustic impedance of the back-matching layer, the back-matching material has an impedance less that the impedance of the transducer layer and the transducer layer has a thickness greater than a of the wavelength of the ultrasound waves the assembly is configured to generate.

A process for manufacturing a transducer assembly is also disclosed.

It is provided a backing layer material resistant to temperature of up to about 600? C. comprising stainless steel powder, cement, water, and optionally at least one adjuvant, a ultrasonic transducer comprising said backing layer material conferring stability to the a ultrasonic transducer to temperature of up to about 600? C.

Assemblies for an ultrasonic probe and manufacturing methods are presented. In one example, the method includes additively forming first portions of the assembly using a first material with first acoustic properties and second portions of the assembly using a second material with second acoustic properties, the first and second acoustic properties being configured to modify ultrasonic signals of the ultrasonic probe. In another aspect, a housing for an ultrasonic probe is presented. The housing includes additively-formed portions, a fluid channel, and at least one cavity. The first additively-formed portions include a first material with first acoustic properties. The second additively-formed portions include a second material with second acoustic properties. The first and second acoustic properties are configured to modify ultrasonic signals of the ultrasonic probe. The fluid channel is for receiving fluid within the housing of the ultrasonic probe.

Transducers are provided including a piezoelectric block having first and second opposing surfaces; a first non-piezoelectric layer on the first surface of the piezoelectric block, the first layer including a low density material having a first thickness; and a second non-piezoelectric layer on the second surface of the piezoelectric block, the second layer including a high density material having a second thickness, the second thickness being different from the first thickness and being at least two times the first thickness. Related devices and methods are also provided.

Disclosed is an ultrasonic transducer including: at least one piezoelectric wafer having two parallel planar main faces: a front face and a posterior face; at least one posterior plate having two parallel planar main faces: an anterior face and a rear face, the anterior face of the posterior plate extending facing, and in contact with, the posterior face of the piezoelectric wafer. The posterior plate has a thickness between three and seven times the thickness of the piezoelectric wafer. The posterior plate has an acoustic impedance between 10 MPa.Math.s.Math.m1 and 35 MPa.Math.s.Math.m1. Also disclosed is a method for assembling such a transducer as well as a flowmeter including at least one such transducer.

A resonance layer (30) and an acoustic separation layer (34) are arranged adjacent to each other between a piezoelectric element (24) and a circuit board (16) provided with an electronic circuit for driving the piezoelectric element. The acoustic impedance of the resonance layer (30) is higher than that of the piezoelectric element (24), and the acoustic impedance of the acoustic separation layer (34) is lower than that of the circuit board (16). An ultrasonic wave is reflected at the interface between the resonance layer (30) and the acoustic separation layer (34) where the difference in acoustic impedance is large, and the ultrasonic wave propagating to the circuit-board (16) side is reduced.

Disclosed are methods, devices, apparatuses, and systems for an under-display ultrasonic fingerprint sensor. A display device may include a platen, a display underlying the platen, and an ultrasonic fingerprint sensor underlying the display, where the ultrasonic fingerprint sensor is configured to transmit and receive ultrasonic waves via an acoustic path through the platen and the display. A light-blocking layer and/or an electrical shielding layer may be provided between the ultrasonic fingerprint sensor and the display, where the light-blocking layer and/or the electrical shielding layer are in the acoustic path. A mechanical stress isolation layer may be provided between the ultrasonic fingerprint sensor and the display, where the mechanical stress isolation layer is in the acoustic path.

Disclosed are methods, devices, apparatuses, and systems for an under-display ultrasonic fingerprint sensor. A display device may include a platen, a display underlying the platen, and an ultrasonic fingerprint sensor underlying the display, where the ultrasonic fingerprint sensor is configured to transmit and receive ultrasonic waves via an acoustic path through the platen and the display. A light-blocking layer and/or an electrical shielding layer may be provided between the ultrasonic fingerprint sensor and the display, where the light-blocking layer and/or the electrical shielding layer are in the acoustic path. A mechanical stress isolation layer may be provided between the ultrasonic fingerprint sensor and the display, where the mechanical stress isolation layer is in the acoustic path.

Disclosed are methods, devices, apparatuses, and systems for an under-display ultrasonic fingerprint sensor. A display device may include a platen, a display underlying the platen, and an ultrasonic fingerprint sensor underlying the display, where the ultrasonic fingerprint sensor is configured to transmit and receive ultrasonic waves via an acoustic path through the platen and the display. A light-blocking layer and/or an electrical shielding layer may be provided between the ultrasonic fingerprint sensor and the display, where the light-blocking layer and/or the electrical shielding layer are in the acoustic path. A mechanical stress isolation layer may be provided between the ultrasonic fingerprint sensor and the display, where the mechanical stress isolation layer is in the acoustic path.

An ultrasonic probe according to one embodiment comprises: a plurality of sound absorbing bodies that form a sound absorbing layer; at least one ground connection part that is joined between the sound absorbing bodies; at least one center connection part that is joined between the sound absorbing bodies and has an electrode; a plurality of side connection parts that are joined between the sound absorbing bodies and disposed outside the center connection part and have an electrode; and a plurality of piezoelectric bodies that are disposed in front of the sound absorbing layer to be electrically connected to the ground connection part, the center connection part, and the side connection parts.