A driving system for driving piezoelectric pump includes one or more mechanical devices and a driving circuit system electrically connected to the at least one mechanical device. The driving circuit system includes a pump-driving unit, a linear voltage-stabilizing unit, a microcontroller unit, a current-sensing unit, and a connection unit. The microcontroller unit generates a first signal, a second signal, and a third signal, and the pump-driving unit receives these signals to drive the mechanical device. The current-sensing unit receives a fourth signal transmitted by the pump-driving unit to obtain an actuation current value of the mechanical device. The linear voltage-stabilizing unit, the current-sensing unit, and the microcontroller unit are coupled to each other through a fifth signal and a sixth signal. The connection unit and the microcontroller unit are coupled to each other through a reset signal, a seventh signal, and an eighth signal provided by the microcontroller unit.

A tunable metamaterial structure can have a flexible substrate that is elastically deformable. The tunable metamaterial structure can have a photo-responsive stiffness-modulating patch. The photo-responsive stiffness-modulating patch can be fixed to a surface of the flexible substrate. The photo-responsive stiffness-modulating patch can include a piezoelectric element and a photo-responsive element. The piezoelectric element and the photo-responsive element are electrically connected to one another.

The present disclosure provides a device having a circuit. The circuit includes at least one boost converter receiving power from an energy source, a square wave driver in series with the boost converter, an inductor in series with the square wave driver for converting a square wave to a sinusoidal wave, and a piezoelectric transducer in series with the inductor, the piezoelectric transducer connectable to a load. The device further includes a phase-locked loop coupled to the circuit to determine a resonance frequency of the piezoelectric transducer when the piezoelectric transducer is connected to the load.

A piezoelectric element includes a plurality of vibration regions that are separated from each other by a slit, and the slit is formed to have a tapered portion that is tapered from a first surface of the vibration regions on an opposite side to a support to a second surface opposite to the first surface. An electrode film is positioned inside than the slit when being viewed from a normal direction orthogonal to the first surface, and an angle formed by a side surface of the tapered portion in the vibration region and a surface parallel to the first surface is in a range of 39 to 81 degrees.

A display apparatus includes: a display panel configured to display an image, and at least one vibration module on a rear surface of the display panel, the at least one vibration module including a piezoelectric composite layer including a plurality of sub-modules configured to vibrate the display panel, each of the plurality of sub-modules including: a plurality of first portions including a piezoelectric characteristic, and a plurality of second portions having flexibility, each of the plurality of second portions being between a respective pair of the plurality first portions, wherein the plurality of first portions in the respective sub-modules are arranged in a same direction or are partially arranged in different directions.

A display apparatus includes: a display panel configured to display an image, and at least one vibration module on a rear surface of the display panel, the at least one vibration module including a piezoelectric composite layer including a plurality of sub-modules configured to vibrate the display panel, each of the plurality of sub-modules including: a plurality of first portions including a piezoelectric characteristic, and a plurality of second portions having flexibility, each of the plurality of second portions being between a respective pair of the plurality first portions, wherein the plurality of first portions in the respective sub-modules are arranged in a same direction or are partially arranged in different directions.

A form birefringent optical element includes a structured layer and a dielectric environment disposed over the structured layer. At least one of the structured layer and the dielectric environment includes a nanovoided polymer, the nanovoided polymer having a first refractive index in an unactuated state and a second refractive index different than the first refractive index in an actuated state. Actuation of the nanovoided polymer can be used to reversibly control the form birefringence of the optical element. Various other apparatuses, systems, materials, and methods are also disclosed.

An ultrasonic probe has a transduction layer in which a plurality of transducers are placed, a backing layer provided at a rear side of the transduction layer with a wiring layer therebetween, and a plurality of heat dissipation members provided in the backing layer. The plurality of heat dissipation members extend in a line form in the backing layer, and are placed with an aligned direction of extension. An area occupancy percentage of the heat dissipation member at a center region of the backing layer is larger than that at an outer side of the center region. The center region is not positioned at ends of the cross section intersecting the direction of extension of the heat dissipation member, includes a center of gravity of the cross section, and occupies an area less than or equal to a half of an area of the cross section.

A spacer with an integrated ribbon cable for insulating glazings includes a main body including two pane contact surfaces, a glazing interior surface, an outer surface, a hollow chamber, and at least one ribbon cable on the outer surface, wherein the ribbon cable is materially bonded to the outer surface.

A transducer includes a first piezoelectric layer; and a second piezoelectric layer that is above the first piezoelectric layer; wherein the second piezoelectric layer is a more compressive layer with an average stress that is less than or more compressive than an average stress of the first piezoelectric layer.