Systems and methods for the ultrasonic disruption of biofilm and algae growth on underwater structures utilize an ultrasonic actuator that produces a natural frequency in the ultrasonic range. In some embodiments, the ultrasonic actuator includes one or more piezoelectric transducers.

Provided are an ultrasonic transducer having a state monitoring function, and an ultrasonic cleaning device using the same. The ultrasonic transducer having a state monitoring function is a Langevin ultrasonic transducer for use in an ultrasonic cleaning device configured to clean an object to be cleaned via cleaning liquid to which ultrasonic vibrations are applied, the ultrasonic transducer having a state monitoring function including a plurality of piezoelectric elements, which are arranged to be stacked on each other, and are expandable and contractable in a direction of the stacking, a part of the plurality of piezoelectric elements serving as a vibration exciting piezoelectric element configured to expand and contract by being applied with an AC voltage, another part of the plurality of piezoelectric elements serving as a state monitoring piezoelectric element configured to output a state monitoring voltage by the expansion and contraction of the vibration exciting piezoelectric element.

A piezo actuator module capable of haptic feedback in a wide frequency range comprises an actuator layer including a piezo actuator having one surface coupled to an object to be excited and vibrating by an electric signal and an inertial mass layer having a certain mass and coupled to the other surface of the actuator layer. The inertial mass layer supports the other surface of the actuator layer when the piezo actuator vibrates.

A data link (101) for a MIMO communication system (100) comprises a first transceiver device (106A) comprising a body (109A) having a transducer mounting surface near or at which is mounted a plurality of first transducers (107A-107D) configured to, in use, receive and convert a plurality of electrical waveforms to a respective plurality of acoustic signals. A first bonding layer (120A) bonds a barrier mounting surface of the body of the first transceiver device to a barrier (103). The data link further comprises a second transceiver device (106B) comprising a body (109B) and a plurality of second transducers (107′A-107′D) configured to receive and convert the plurality of acoustic signals transmitted through the barrier to a respective plurality of electrical waveforms. A second bonding layer (120B) bonds a barrier mounting surface of the body of the second transceiver to the barrier.

The ultrasonic tubular transducer is activated at the centre thereof by two symmetrical electromechanical converters. The vibration generated by the two electromechanical converters is converted and then transmitted to the tube via a coupler. The ultrasonic transducer can be vibrationally isolated from the interfaces thereof by caps equally suitable for connecting the transducer to a stationary frame, a free end or another similar ultrasonic transducer. A device for pre-stressing electromechanical converters has a hole bored at the centre thereof in order to allow cables from the transducer as well as from adjacent transducers to pass therethrough.

A lead-free piezoelectric ceramic composition mainly includes a first crystal phase (KNN phase) and a second crystal phase (NTK phase). In the first crystal phase (KNN phase), a plurality of crystal grains formed of an alkali niobate/tantalate perovskite oxide having piezoelectric characteristics is bound to each other in a deposited state. The second crystal phase (NTK phase) is formed of a compound containing titanium (Ti) and fills spaces between the crystal grains in the first crystal phase.

An acoustic wave generator including a stack having a plurality of first layers configured to receive electrical and/or magnetic energy and a plurality of second layers configured in contact with the plurality of first layers, the plurality of second layers comprising one or more materials configured to change mechanical properties when electrical and/or magnetic energy is applied thereto. The generator further having at least one source configured in operational communication with the plurality of first layers and configured to supply at least one of phased electrical and/or magnetic energy to the plurality of first layers, wherein the stack is configured to (i) generate phased acoustic energy and (ii) at least one of amplify and store the generated phased acoustic energy in a first state and release said generator acoustic energy in a second state.

An electrolytic water softener which comprises a container, at least one cathode and at least one anode extending into the container, a power supply operatively connected to the cathode and anode, a vibrating device to vibrate the cathode, and a system for collecting material released from the cathode after operation of the vibration device.

An array of piezoelectric micromachined ultrasonic transducers (PMUTs) includes a first piezoelectric layer and a second piezoelectric layer, a dielectric layer positioned between the first piezoelectric layer and the second piezoelectric layer, and a plurality of conductive layers positioned on opposing surfaces of the first piezoelectric layer and opposing surfaces of the second piezoelectric layer. A plurality of isolation trenches extend through the dielectric layer and at least a portion of conductive layers of the plurality of conductive layers, where the plurality of isolation trenches are positioned between neighboring PMUTs of the array of PMUTs such that the neighboring PMUTs are electrically isolated, and wherein the plurality of isolation trenches relieve stress in the dielectric layer.

A ultrasonic transducer assembly of an ultrasonic surgical instrument includes a horn, a piezoelectric stack positioned proximally of the horn and defining a longitudinal opening extending therethrough, a proximal end mass positioned proximally of the piezoelectric stack and defining a longitudinal opening, and a rod secured to the horn and extending proximally from the horn through the longitudinal opening of the piezoelectric stack and the longitudinal opening of the proximal end mass. The rod is secured to the proximal end mass to pre-compress the piezoelectric stack between the horn and the proximal end mass.