A structure that prevents a substrate from being warped is provided on a region or a location other than a membrane that determines the characteristics of a CMUT. In a CMUT in a structure in which a first conductive layer and a second conductive layer are provided sandwiching a cavity on a substrate, for example, as a warpage prevention structure, a warpage prevention layer that prevents the substrate from being warped is provided between the substrate and the first conductive film. When the insulating film disposed between the cavity and the first conductive film and the insulating film disposed between the cavity and the second conductive film are silicon oxide films, the warpage prevention layer includes a silicon nitride film.

Acoustic perfusion devices for separating biological cells from other material in a fluid medium are disclosed. The devices include an inlet port, an outlet port, and a collection port that are connected to an acoustic chamber. An ultrasonic transducer creates an acoustic standing wave in the acoustic chamber that permits a continuous flow of fluid to be recovered through the collection port while keeping the biological cells within the acoustic chamber to be returned to the bioreactor from which the fluid medium is being drawn.

An ultrasonic welding device for ultrasonic welding of members to be welded, comprising: an ultrasonic horn configured to generate ultrasonic vibration; a horn chip configured to transmit the ultrasonic vibration to the members to be welded; and a connecting member provided between the ultrasonic horn and the horn chip for connecting them. The ultrasonic horn has a first screw part at the tip. The horn chip has a second screw part at the base end. The connecting member has a third screw part at one side to be screwed with the first screw part and a fourth screw part at the other side to be screwed with the second screw part. The ultrasonic horn and the horn chip are connected by the connecting member so that the attachment surface of the ultrasonic horn and the attachment surface of the horn chip are pressed to each other.

To provide a tactile vibration applying device that efficiently outputs vibrations using an electrostatic or piezoelectric actuator. The tactile vibration applying device includes the electrostatic or piezoelectric actuator formed in a flat shape, and expanding and contracting in a thickness direction, a first elastic body having an elastic modulus smaller than an elastic modulus of the actuator in the thickness direction and disposed to contact a surface of the actuator on a side of the first electrode, and a first cover covering a surface of the first elastic body opposite to a surface of the first elastic body contacting the actuator, pressing the actuator and the first elastic body in the thickness direction of the actuator, and holding the first elastic body in a state that the first elastic body is compressed more than the actuator.

Acoustic perfusion devices for separating biological cells from other material in a fluid mixture are disclosed. The devices include an inlet port, an outlet port, and a collection port that are connected to an acoustic chamber. An ultrasonic transducer creates an acoustic standing wave in the acoustic chamber that permits a continuous flow of fluid to be recovered through the collection port while keeping the biological cells within the acoustic chamber to be returned to the bioreactor from which the fluid mixture is being drawn.

A front mass of a vibration generating unit included a flange portion supported, and a block portion provided on a proximal side with respect to the flange portion. A distal end of the element unit abuts on a proximal end of the block portion. Ultrasonic vibration generated in a piezoelectric element is transmitted, thereby vibrating the front mass in a predetermined frequency region where a referential vibration anti-node, which is one of vibration anti-nodes located on the proximal side with respect to the flange portion, is located at a boundary position between the block portion and the element unit or in the vicinity of the boundary position.

An ultrasonic device includes: an element substrate including an ultrasonic transducer and a first connection electrode connected to the ultrasonic transducer; a reinforcing plate that is bonded to the element substrate to reinforce the element substrate; and a second connection electrode provided on the reinforcing plate. The first and second connection electrodes are connected to each other in a bonding portion between the element substrate and the reinforcing plate.

Acoustic perfusion devices for separating biological cells from other material in a fluid mixture are disclosed. The devices include an inlet port, an outlet port, and a collection port that are connected to an acoustic chamber. An ultrasonic transducer creates an acoustic standing wave in the acoustic chamber that permits a continuous flow of fluid to be recovered through the collection port while keeping the biological cells within the acoustic chamber to be returned to the bioreactor from which the fluid mixture is being drawn.

A method for effectively cleaning vias (20034), trenches (20036) or recessed areas on a substrate (20010) using an ultra/mega sonic device (1003, 3003, 16062, 17072), comprising: applying liquid (1032) into a space between a substrate (20010) and an ultra/mega sonic device (1003, 3003, 16062, 17072); setting an ultra/mega sonic power supply at frequency f.sub.1 and power P.sub.1 to drive said ultra/mega sonic device (1003, 3003, 16062, 17072); after the ratio of total bubbles volume to volume inside vias (20034), trenches (20036) or recessed areas on the substrate (20010) increasing to a first set value, setting said ultra/mega sonic power supply at frequency f.sub.2 and power P.sub.2 to drive said ultra/mega sonic device (1003, 3003, 16062, 17072); after the ratio of total bubbles volume to volume inside the vias (20034), trenches (20036) or recessed areas reducing to a second set value, setting said ultra/mega sonic power supply at frequency f.sub.1 and power P.sub.1 again; repeating above steps till the substrate (20010) being cleaned.

A method for the quality inspection of an ultrasonic transducer and an ultrasonic sensor comprising an ultrasonic transducer and carrying out the quality inspection method are described. The ultrasonic transducer comprises a housing having an electrically conductive layer extending at least over an inner surface of a housing wall of the housing, and a piezoelectric transducer arranged in the housing, the end face of which equipped with an electrode is connected to the electrically conductive layer by means of a dielectric coupling layer. According to the method, at least one quality inspection of the ultrasonic transducer is carried out, in which a capacitance of a capacitor comprising the electrode, the electrically conductive layer serving as the counter electrode, and the dielectric coupling layer as a dielectric is measured and a quality defect of the ultrasonic transducer is determined if the measured capacitance is outside a specified capacitance range.