The invention relates to a system and a method for controlling an ultrasound generator of a machine tool for generating ultrasound for machining a workpiece. According to the invention, a determined phase shift of the ultrasound is analyzed as a function of frequency and, based on the analysis, a regulation algorithm for controlling the frequency of the ultrasound generated by the ultrasound generator is determined.

A piezoelectric micromachined ultrasonic transducer (PMUT) device includes a layer of piezoelectric material that is activated and sensed by an electrode and a conductive plane layer. The conductive plane layer may be electrically connected to processing circuitry by a via that extends through the piezoelectric layer. One or more isolation trenches extend through the conductive plane layer to isolate the conductive plane layer from other conductive plane layers of adjacent PMUT devices of a PMUT array.

An ultrasonic sensing module, an ultrasonic sensing device and a control method thereof, and a display device. The ultrasonic sensing module includes a first electrode layer, a piezoelectric layer, a receiving electrode layer and an emission electrode layer. The first electrode layer is on a first side of the piezoelectric layer; the receiving electrode layer and the emission electrode layer insulated from the receiving electrode layer are on a second side of the piezoelectric layer; and the second side is opposite to the first side.

A display apparatus includes: a display panel; an enclosure enclosing the display panel; a cover member covering a front surface of the display panel; an actuator connected to the cover member and having a function of applying vibration to the cover member; and a viscous body arranged between the display panel and the cover member. The viscous body is bonded to the display panel and the cover member, and, when a periodic stress having a vibration frequency of ½ period per second is applied to the viscous body, a dynamic elastic modulus of the viscous body is equal to or lower than 1×10.sup.−3 of Young's modulus of the viscous body.

An apparatus comprising an array of polymer-based capacitive micromachined ultrasonic transducers positioned on a substrate. The substrate may be at least substantially transparent to ionizing radiation, be flexible, and/or have walls positioned thereon to protect the transducers.

An ultrasound imaging device includes: a first transmitter configured to transmit a transmission signal to at least one piezoelectric element; a receiver configured to receive a reception signal from the at least one piezoelectric element; a second transmitter configured to transmit a given signal to the at least one piezoelectric element; a timing controller configured to control a transmitting timing at which the first transmitter transmits the transmission signal and a receiving timing at which the receiver receives the reception signal; and a signal controller configured to cause the second transmitter to transmit the given signal to a first area to which the first transmitter does not transmit the transmission signal at the transmitting timing or cause the second transmitter to transmit the given signal to a second area from which the receiver does not receive the reception signal at the receiving timing.

A drive control device is provided that vibrates a vibrating body by applying signals having mutually different phases to a plurality of electrodes provided at a piezoelectric element on the vibrating body. The drive control device includes a signal application unit that selectively applies a signal to an electrode of the plurality of electrodes; an amplitude detection unit that receives a feedback signal from an electrode different from the electrode to which the signal application unit has performed selective application; and a signal condition control unit that controls a condition of a signal to be applied by the signal application unit based on the feedback signal.

A system includes sensor-actuator units fixed onto a plate to be actuated according to at least one predetermined vibratory mode, each sensor-actuator unit having an electromechanical actuator and a deformation or vibratory speed sensor, wherein the electromechanical actuator and the sensor are colocated on the surface, that is to say that the measurement by the sensor is performed in immediate proximity to the electromechanical actuator, this proximity being such that the actuator and the sensor can respectively actuate and measure the same predetermined vibratory mode.

An MEMS device includes: a first member; a second member forming a sealed space with the first member therebetween; and a third member disposed between the first member and the second member and joined to the first member and the second member, in which the third member has lower rigidity than rigidity of the first member and the second member, and the third member is provided with a communication portion that establishes communication between the sealed space and an external space.

Micromachined ultrasonic transducers integrated with complementary metal oxide semiconductor (CMOS) substrates are described, as well as methods of fabricating such devices. Fabrication may involve two separate wafer bonding steps. Wafer bonding may be used to fabricate sealed cavities in a substrate. Wafer bonding may also be used to bond the substrate to another substrate, such as a CMOS wafer. At least the second wafer bonding may be performed at a low temperature.