A unit and a tactile sensation providing apparatus which enable simplification of the assembly process of the apparatus are provided. The unit is provided with an actuator, a first fixing unit fixable to a base, a second fixing unit, and an elastic member configured to couple the first fixing unit and the second fixing unit together. The second fixing unit is fixable to a vibration object and coupled to the actuator.

An acoustic logging tool includes a first acoustic transducer and a second acoustic transducer. At least a portion of the first transducer is parallel with the second transducer. The first and second acoustic transducers are configured to propagate an acoustic signal in the same direction. The first acoustic transducer is configured to generate an acoustic output having a different frequency than the second acoustic transducer.

In an ultrasonic transducer assembly, a conformable ultrasonic transducer has a piezoelectric layer and electrodes able to conform to curved surfaces, and a clamp for pressing the transducer into ultrasonic contact with a curved surface. Conformability is ensured with a thin, porous piezoelectric layer and suitable electrical conductors and insulators. The ultrasonic transducer may operate without further thermal shielding under harsh environments and/or at high temperatures.

An acoustic transducer (30), comprising: a support structure (36); an active assembly comprising a base plate (32) supported by the support structure (36) and a piezoelectric body (34) supported by the base plate (32); and a passive vibrator (38) supported by the support structure (36) and coupled via the support structure (36) to the active assembly (32, 34) so that vibration of the active assembly (32, 34) drives the passive vibrator (38). The active assembly (32, 34) and the passive vibrator (38) have the same resonant frequency.

An array of micromachined ultrasonic transducers (MUTs). The array has first and second rows, the MUTs in the first row being equally spaced by a horizontal pitch in a horizontal direction, the MUTs in the second row being equally spaced by the horizontal pitch in the horizontal direction. The MUTs in the second row are shifted along the horizontal direction by a first horizontal distance relative to the MUTs in the first row and shifted along a vertical direction by a first vertical distance relative to the MUTs in the first row. The first horizontal distance is greater than zero and less than the horizontal pitch. The first vertical distance ranges from one tenth of a horizontal width of a MUT to a half of a vertical height of a MUT.

A sound generator includes at least one piezoelectric vibrator including a piezoelectric element, a vibration unit in one of a non-contact state not contacting the at least one piezoelectric vibrator and a contact state contacting the at least one piezoelectric vibrator. While in the contact state, the at least one piezoelectric vibrator generates vibration in response to a signal, and causes a contact surface contacted by the vibration unit to vibrate and generate a sound to be emitted from the contact surface. The sound generator can detect driving allowed and driving denied states, and control application of a sound signal in accordance with the two states to the piezoelectric element.

A device (100) for the excitation of a fiber (150) comprises a first piezo bender actuator (110) and a second piezo bender actuator (120). The device (100) also comprises a connection part (130) which is arranged between the first piezo bender actuator (110) and the second piezo bender actuator (120). The device (100) also comprises a movable fiber (150) which is mounted to the connection part (130).

A bender bar transducer having stacked encapsulated actuators provides improved acoustic power over a wider frequency range, low applied voltage requirements and consistent part-to-part performance.

An improved domain transformation method for a dispersive ultrasonic guided wave signal, including the following steps: obtaining a dispersive wave number curve and a non-dispersive wave number curve corresponding to a mode of an ultrasonic guided wave signal; calculating an ultrasonic guided wave excitation waveform that is in distance domain and that has a reduced space width; obtaining an ultrasonic guided wave impulse response signal in distance domain; and calculating and obtaining a non-dispersive ultrasonic guided wave distance-domain signal whose resolution is enhanced.

An effective bandwidth in a membrane based ultrasonic transducer is improved by a control element (C). The control element (C) is disposed on a first side (10a) of a first membrane (10) of the transducer to increase or decrease a displacement amplitude of the first membrane (10) towards the first side (10a) and/or the opposite, second side (10b). This induces a displacement asymmetry (Za< >Zb) in a motion of the first membrane (10) during a first vibration (V1) of the first membrane (10) to the first side (10a) compared to the second side (10b). The displacement asymmetry may result in improved bandwidth.