A MEMS device may include a first electrode region; a first piezoelectric layer arranged over the first electrode region; a second electrode region arranged over the first piezoelectric layer; a second piezoelectric layer arranged over the first piezoelectric layer and the second electrode region; a third electrode region arranged over the second piezoelectric layer; a first input port coupled to the first electrode region and/or the second electrode region for providing a first electrical signal to the first piezoelectric layer to generate a first vibration in the first piezoelectric layer; a second input port coupled to the second electrode region and/or the third electrode region for providing a second electrical signal to the second piezoelectric layer to generate a second vibration in the second piezoelectric layer; and an output port configured to receive an output signal including a superposition of the first vibration and the second vibration.

The present invention includes: an ultrasonic horn (14) to which two ultrasonic vibrations can be input to excite a capillary (15) mounted to a front end with different frequencies in a Y-direction and an X-direction; and a control unit (50) which adjusts the respective magnitude of the two ultrasonic vibrations. The Y-direction is a direction in which the ultrasonic horn (14) extends. The control unit (50) adjusts the respective magnitude of the two ultrasonic vibrations to adjust a ratio (ΔY/ΔX) of amplitude of the capillary (15) in the Y-direction and the X-direction. Thus, degradation in the quality of the joining between wires and leads is suppressed.

Systems and methods to remediate, degrade, and/or remove pollutants within various contaminated environmental solid media that includes contaminated soils and sediments, biosolids and slurries by subjecting a mixture of the contaminated solids and a liquid to acoustic cavitation generated by more than one type of ultrasonic device. One of the ultrasonic devices operates at a low frequency and the other ultrasonic device operates at a high frequency. The system advantageously provide an efficient, sustainable, and easy to handle approach to degrade contaminant, requiring only electrical energy

The present invention relates to a haptic feedback system and, specifically, to a device and method for controlling an actuator for haptic feedback, the method comprising: an actuator resonance frequency correction driving step of driving an actuator by repeatedly generating and outputting a drive signal including a driving time interval in which driving voltage is applied to the actuator and a guard time interval in which a back electromotive force (BEMF) signal of the actuator is detected, while correcting the length of the driving time interval according to detection time of a zero cross point of the BEMF signal detected within the guard time interval; and an actuator braking step of outputting at least one brake signal in synchronization with a zero cross point of the BEMF signal detected within the guard time interval, in order to remove residual vibration of the actuator.

Provided is a driving apparatus that sets a signal wave in a low-frequency region having a frequency of 10 Hz or more and 250 Hz or less as a modulating wave and outputs to a piezoelectric actuator a driving signal having a waveform obtained by modulating an amplitude of a sine wave in a high-frequency region having a frequency of 20 kHz or more and 40 kHz or less with the modulating wave.

Provided herein are methods of capturing particulates. The methods may include contacting particulates in a gas stream with one or more acoustic waves. The one or more acoustic waves may include standing waves or waves of modulating frequency. The methods may include promoting agglomeration of particulates with an electrostatic force. Also provided herein are systems for capturing particulates.

The method and system uses ultrasound (US) transducers in contact with an inboard surface underwater portions of marine vessels or structures. By first digitally generating disruptive, multi-frequency, interfering US waveform signals (complex waveforms, typically replicating a Bessel function) and then converting the signals into analog, the transducers generate disruptive, multi-frequency, interfering US waveforms through the underwater portions of the marine vessels and structures which waveforms disrupt unwanted marine growth on the water-side of the vessel or structure. The digital signals, and also the analog signals, are complex waveform signals, typically produced with a Bessel function. The US transducers are either circular membrane transducers or surface transducers. A computer processor coupled to a memory, generates the complex waveform signals fed to the US transducers.

A vibration device is provided that includes a vibration element with a piezoelectric vibrator and a driving device that causes the vibration element to vibrate. The vibration element includes a translucent body and the piezoelectric vibrator is electrically coupled to the driving device. The driving device includes a first circuit that applies an electric signal to the piezoelectric vibrator to render the vibration element in a resonant state, a second circuit that applies an electric signal to the piezoelectric vibrator according to a feedback signal output from the piezoelectric vibrator, and a switch that switches coupling between the first circuit and the piezoelectric vibrator and coupling between the second circuit and the piezoelectric vibrator at a certain timing.

A method for identifying a mechanical impedance of an electromagnetic load may include generating a waveform signal for driving an electromagnetic load, the waveform signal comprising a first tone at a first driving frequency and a second tone at a second driving frequency. The method may also include during driving of the electromagnetic load by the waveform signal or a signal derived therefrom, receiving a current signal representative of a current associated with the electromagnetic load and a back electromotive force signal representative of a back electromotive force associated with the electromagnetic load. The method may further include determining amplitude and phase information of the current signal responsive to the first tone and second tone, determining amplitude and phase information of the back electromotive force signal responsive to the first tone and second tone, and identifying parameters of the mechanical impedance of the electromagnetic load based on the amplitude and phase information of the current signal and the amplitude and phase information of the back electromotive force signal.

A multi-frequency ultrasound therapy apparatus is configured to operate at its center frequency and at the higher harmonic of its center frequency. The center frequency can be for the entire apparatus or for each ultrasound source element. At least one source element can generate ultrasound energy at its center frequency while, simultaneously, at least another source element can generate ultrasound energy at the higher harmonic of its center frequency. In addition, the same source element can generate ultrasound energy at its center frequency and the higher harmonic of its center frequency, respectively, but at different times. A data storage unit that stores encrypted and encoded data is disposed on the apparatus. The encoded data includes a unique identification code of the apparatus, the condition of use of the apparatus, the center frequency of each source element, the ultrasound efficiency of each source element, and/or other parameters relating to the apparatus.