There is provided a piezoelectric stack, including: a substrate; an output-side bottom electrode film on the substrate; an output-side piezoelectric film, being an oxide film, on the output-side bottom electrode film; an output-side top electrode film on the output-side piezoelectric film; an input-side bottom electrode film on the substrate; an input-side piezoelectric film, being a nitride film, on the input-side bottom electrode film; an input-side top electrode film on the input-side piezoelectric film; and an ultrasonic output part and ultrasonic input part placed in such a manner as not overlapping each other when viewed from a top surface of the substrate, the ultrasonic output part comprising a stacked part of the output-side bottom electrode film, the output-side piezoelectric film, and the output-side top electrode film, the ultrasonic input part comprising a stacked part of the input-side bottom electrode film, the input-side piezoelectric film, and the input-side top electrode film.

Aspects of the present disclosure describe systems, methods, and structures that scavenge mechanical energy to provide electrical energy to a wearable, where the mechanical energy is scavenged by a bending-strain-based transducer that includes a non-resonant energy harvester. By employing a non-resonant energy harvester that operates in bending mode, more electrical energy can be generated that possible with prior-art energy harvesters. In some embodiments, the output of a bending-strain-based transducer element is used for both energy scavenging and as a sensor signal indicative of a user parameter, such as a step, respiration rate, heart rate, weight and the like. In some embodiments, a transducer element includes a plurality of piezoelectric layers that are electrically connected in parallel to increase the energy and/or power provided by the transducer element.

An optical device includes: an optical element; a housing unit configured to accommodate the optical element; a support part configured to pivotally support the optical element to be tiltable with respect to the housing unit; a piezoelectric element configured to connect the optical element and the housing unit to each other; and an electrode arranged at the piezoelectric element.

A microelectromechanical apparatus includes a base and a thin film including a stationary part disposed on the base, a peripheral part, a central part surrounded by the peripheral part, and a first and second elastic part. The first elastic part is connected to the stationary part and the peripheral part. The second elastic part is connected to the peripheral part and the central part. When low frequency signal is input to a first electrode of the first elastic part, the peripheral part and the and the central part respectively vibrate with a first and second low-frequency amplitudes. When high-frequency signal is input to a second electrode of the second elastic part, the peripheral part and the central part respectively vibrate with a first and second high-frequency amplitudes. A difference between the first and second low-frequency amplitudes is smaller than a difference between the first and second high-frequency amplitudes.

A microfluidic-based device and system is disclosed for the high-throughput intracellular delivery of biomolecular cargo to cells (eukaryotic or prokaryotic) or enveloped viruses. Cargo integration occurs due to transient membrane permeabilization by exposure to bulk acoustic waves (BAWs) transduced from surface acoustic waves (SAWs) generated by a rapidly oscillating piezoelectric substrate. In this approach, temporary pores are established across the cellular membrane as cells are partially deformed and squeezed or subject to shearing forces as they travel through the vibrational modes created within the microfludic channel(s) of the device.

A quartz crystal resonator unit including a quartz crystal resonator having a quartz crystal blank, a frame surrounding an outer periphery of the quartz crystal blank, and coupling members connecting the frame to the quartz crystal blank. Moreover, a lid member and a base member are attached to the frame and seal the resonator. One or more outer electrodes is formed over end surfaces of the frame, the lid member, and the base member on a side where the coupling members are coupled. The one or more outer electrodes has a machinery quality factor smaller than that of the frame.

This application relates to methods and apparatus for driving a transducer with switching drivers. A driver circuit has first and second switching drivers for driving the transducer in a bridge-tied-load configuration, each of the switching drivers having a respective output stage for controllably switching the respective driver output node between high and low switching voltages with a controlled duty cycle. Each of switching drivers is operable in a plurality of different driver modes, wherein the switching voltages are different in said different driver modes. A controller controls the driver mode of operation and the duty cycle of the switching drivers based on the input signal. The controller is configured to control the duty cycles of the first and second switching drivers within defined minimum and maximum limits of duty cycles; and to transition between driver modes of operation when the duty cycle of one of the switching drivers reaches a duty cycle limit.

Transducer systems disclosed herein include self-sensing capabilities. In particular, electrostatic transducers include a low voltage electrode and a high voltage electrode. A low voltage sensing unit is coupled with the low voltage electrode of the electrostatic transducer. The low voltage sensing unit is configured to measure a capacitance of the electrostatic transducer, from which displacement of the electrostatic transducer may be calculated. High voltage drive signals received by the high voltage electrode during actuation may be isolated from the low voltage sensing unit. The isolation may be provided by dielectric material of the electrostatic transducer, a voltage suppression component, and/or a voltage suppression module comprising a low impedance ground path. In the event of an electrical failure of the transducer, the low voltage sensing unit may be isolated from high voltages.

The electrical energy conversion system comprises: a converter including E first switching assembly or assemblies, each associated with an input voltage and including two first switches; N second switching assembly or assemblies, each associated with an output voltage and including two second switches; and at least one piezoelectric assembly connected to a switch; E>1, N>1; a control device configured for controlling, during a resonance cycle, a switching of the switches so as to alternate phases at constant voltage and phases at constant load across said piezoelectric assembly or assemblies.

The converter comprising an electrical transformer having a primary winding connected to a first switching assembly and a secondary winding connected to a second switching assembly, and each piezoelectric assembly being connected between a switch and a winding.

A piezoelectric system includes a piezoelectric resonator comprising a piezoelectric element and a pair of electrodes configured to transmit signals emitted by the piezoelectric element and generated by a deformation of the piezoelectric element; a detector configured to detect at least two signals of the signals generated by the deformation of the piezoelectric element, the at least two signals being detected at different instants; a control unit configured to compare the at least two signals and, on the basis of the comparison, determine a complex active impedance value as a function of a predetermined law; an active impedance unit configured to generate an active impedance based on the complex active impedance value determined by the control unit, the active impedance being connected to the pair of electrodes.