A method of operating a multi-axis fiber scanner having a base including a base plane includes providing a source of electromagnetic radiation, directing the electromagnetic radiation through a fiber link that passes through the base plane of the base along a longitudinal axis orthogonal to the base plane, and supporting a retention collar positioned a distance from the base plane. The method also includes actuating a first piezoelectric actuator among a plurality of piezoelectric actuators to decrease the distance between a first side of the base and the retention collar, actuating a second piezoelectric actuator among the plurality of piezoelectric actuators to increase the distance between a second side of the base and the retention collar, and scanning the fiber link in a scanning plane.

A communication system may communicate by backscattered acoustic signals that propagate through a liquid or solid. In this system, one or more transmitters may transmit acoustic signals that travel to, and are reflected by, an acoustic backscatter node. The backscatter node may modulate the amplitude and/or phase of the reflected acoustic signals, by varying the acoustic reflectance of a piezoelectric transducer onboard the node. The modulated signals that reflect from the backscatter node may travel to a microphone and may be decoded. The backscatter node may include sensors, and the uplink signals may encode sensor readings. The backscatter node may harvest energy from the downlink acoustic signals, enabling the node and the sensors to be battery-free. Multiple backscatter nodes may communicate concurrently at different acoustic frequencies. To achieve this, each node may have a matching circuit with a different resonant frequency.

An ultrasonic transducer may comprise a transducer body including a first face and a second face disposed on opposite sides of the transducer body, wherein the transducer body comprises a piezoelectric material; a first transducer edge disposed on the transducer body; and a second transducer edge disposed on the transducer body, wherein the first edge is disposed on the transducer body substantially opposite from the second edge, and wherein the first and second transducer edges intersect a perimeter of the transducer body, and wherein the first and second edge forms an angle no less than 3 degrees.

A cylindrical piezoelectric transducer is described the cylindrical piezoelectric transducer comprising: a tube having inner and outer surfaces and a first inner diameter, first outer diameter and a first thickness; at least one stepped band having a stepped inner diameter, stepped outer diameter and stepped thickness and wherein the stepped thickness is less than the first thickness and the at least one stepped bands are spaced along the length of the tube and alternate with bands of the first thickness; and conductive material disposed over the inner and outer surfaces of the tube.

Pressure vessels that operate at elevated temperatures and pressures (e.g., 600 F./316 C., 20000 psig), and ultrasonic transducers and signal connectors for use therein, are described. The pressure vessels include a housing defining a cavity. The housing includes a cylindrical body with plugs positioned within openings of the cylindrical body. Each plug has a recess extending from an external surface to a location ultrasonically adjacent the cavity. The pressure vessels additionally include transducer assemblies positioned within respective plug recesses. Each transducer assembly includes a signal connector positioned within the recess adjacent the external surface, a transducer having a piezoceramic element positioned within the recess at the location ultrasonically adjacent the cavity, and a metallic interconnection spring interconnecting the transducer to the signal connector.

A multi-element fiber scanner for scanning electromagnetic imaging radiation includes a base having a base plane and a longitudinal axis orthogonal to the base plane and a fiber link passing through the base in a direction parallel to the longitudinal axis. The fiber link is operatively coupled to at least one electromagnetic radiation source. The multi-element fiber scanner also includes a retention collar disposed a predetermined distance along the longitudinal axis from the base and a first set and a second set of piezoelectric tubes. First and second piezoelectric tubes of the first set are joined to the base and extends from the base and first and second piezoelectric tubes of the second set are joined to the retention collar and extend from the retention collar.

A vibrating piezoelectric atomizer comprising: a piezoelectric tube having a length, a first end defining an opening and a second end, the second end of the piezoelectric transducer tubular body is connected to a horn; the horn is dimensioned to be half wavelength resonator; the horn is folded and located alongside the piezoelectric tube; a metallic disk is connected to the horn near the first end of the piezoelectric tube, whereby by applying an alternating voltage across electrodes of the piezoelectric tube, the piezoelectric tube is excited into a resonant vibration when frequency of excitation equals to half wavelength resonant frequency of the piezoelectric tube's length and vibrates in synchronism and is communicated to the metallic disk to atomize a liquid.

Systems and methods for monitoring organisms within an aquatic environment are described. According to one aspect, an injectable acoustic transmission device includes a body configured to be injected inside of an organism, a transducer within the body and configured to convert a plurality of electrical signals into a plurality of data transmissions which are transmitted externally of the body and the organism, a plurality of circuit components within the body and configured to use electrical energy from a power source to generate the electrical signals which are provided to the transducer, and wherein the transducer defines an internal volume and at least one of the circuit components is provided within the internal volume of the transducer.

An ultrasonic transducer includes: a piezoelectric element having a plate-like shape and an area expansion vibration mode; and a vibration surface separated from main surfaces thereof and arranged in parallel to the main surfaces so as to be brought into contact with a liquid; a piezoelectric element receiving portion held in contact with a side surface of the piezoelectric element and configured to fix the piezoelectric element; and a vibration transmitting portion; and the vibration member having a space for surrounding the main surface formed by the vibration surface, the piezoelectric element receiving portion, and the vibration transmitting portion, wherein a vibration generated by the piezoelectric element is transmitted to the vibration surface through the piezoelectric element receiving portion and the vibration transmitting portion, and the vibration surface is vibrated in a direction orthogonal to a vibration direction in the area expansion vibration mode.

An acoustic transducer, in particular for an ultrasonic sensor, is proposed. The acoustic transducer has a functional group, the functional group encompassing a diaphragm cup and at least one electroacoustic transducer element. The acoustic transducer furthermore has a housing. The diaphragm cup encompasses a vibration-capable diaphragm and an encircling wall, as well as at least one electroacoustic transducer element, the transducer element being embodied to excite the diaphragm to vibrate and/or to convert vibrations of the diaphragm into electrical signals. The diaphragm cup is constituted from a plastic material, the at least one transducer element being integrated into the vibration-capable diaphragm, the transducer element having an electrically active polymer.