A vibrator includes: a base portion; a vibrating arm including an arm portion which extends from the base portion, and a weight portion which is located on a tip end side of the arm portion and which has a first main surface and a second main surface that are in a front-back relationship; and a weight film disposed at the first main surface of the weight portion. The first main surface includes a first planar surface, a second planar surface which is located closer to the second main surface than is the first planar surface and which is parallel to the first planar surface, and an inclined surface which couples the first planar surface and the second planar surface and which forms an angle of 100° or less with the first planar surface. A method for manufacturing a vibrator includes: a preparation step of preparing the above-described vibrator; and a removing step of removing a part of the weight film by emitting an energy ray to the weight film from a normal direction of the first planar surface.

A cooling system is described. The cooling system includes a cooling element having a central region and a perimeter. The cooling element is anchored at the central region. At least a portion of the perimeter is unpinned. The cooling element is in communication with a fluid. The cooling element is actuated to induce vibrational motion to drive the fluid toward a heat-generating structure.

A thin film actuator having transversely oriented structural stiffeners that serve to increase actuation stroke that results from longitudinal curvature. The thin film actuator may be deployed within electromechanical devices such that an actuatable deflection of a tip of the actuator plate produces the actuation stroke. The thin film actuator may include an actuator plate affixed to a substantially rigid frame structure. The actuator plate protrudes along a longitudinal axis away from the frame structure such that the actuator plate is cantilevered from the frame structure by some distance along this longitudinal axis. The thin film actuator includes a piezoelectric film on a surface of the actuator plate. Activation of the piezoelectric film generates tensile stress or compressive stress at the surface, thereby inducing a bending moment that causes the actuator plate to undergo longitudinal curvature and some lesser degree of transverse curvature.

A piezoelectric element includes a piezoelectric layer, a first electrode layer, a second electrode layer, and a connecting electrode. The piezoelectric layer includes first and second surfaces, and a through-hole. The second electrode layer is adjacent to the second surface of the piezoelectric layer. The second electrode layer faces the through-hole. The second electrode layer includes silicon as a major component. The connecting electrode is on a connecting surface of the second electrode layer, and the connecting surface faces the through-hole. The connecting electrode is made of a metal. A surface roughness of the connecting surface is greater than a surface roughness of a major surface. The major surface is a portion, other than the connecting surface, of a surface of the second electrode layer, and the surface is adjacent to the piezoelectric layer.

A system includes an active micro-electric mechanical system (MEMS) cooling system and a drive system. The MEMS cooling system includes cooling element(s) that direct fluid toward a surface of heat-generating structure(s) when driven to vibrate by a driving signal having a frequency and an input voltage. The drive system is coupled to the active MEMS cooling system and provides the driving signal. The drive system includes a power source and a feedback controller providing a feedback signal corresponding to a proximity to a resonant state of the at least one cooling element. The drive system adjusts at least one of the frequency and the input voltage based on the feedback signal such that the frequency corresponds to the resonant state of the cooling element(s). The input voltage does not exceed a maximum safe operating voltage for the cooling element(s).

A vacuum transistor includes a substrate and a first terminal formed on the substrate. A piezoelectric element has a second terminal formed on the piezoelectric element, wherein the piezoelectric element is provided over the first terminal to provide a gap between the first terminal and the second terminal. The gap is adjusted in accordance with an electrical field on the piezoelectric element.

The present disclosure discloses a piezoelectric self-powered combination beam vibration damper and a control method thereof. An upper guiding component is installed inside an upper rigid frame, a lower guiding component is installed inside a lower rigid component, a guide rod is nested inside the upper guiding component and the lower guiding component, an upper elastic component is sleeved outside the upper idler wheel mechanism, a lower elastic component is sleeved outside the lower idler wheel mechanism, one end of each piezoelectric cantilever beam is fixed between the upper rigid frame and the lower rigid frame, the other end of each piezoelectric cantilever beam is arranged between the upper idler wheel mechanism and the lower idler wheel mechanism, at least one piezoelectric cantilever beam is connected with the input end of a circuit system, and other piezoelectric cantilever beams are connected with the output end of the circuit system.

A ferroelectric material includes a mixed crystal having AlN and at least one nitride of a transition metal. The proportion of the nitride of the transition metal is selected such that a direction of an initial or spontaneous polarity of the ferroelectric material is switchable by applying a switchover voltage. The switchover voltage is below a breakdown voltage of the ferroelectric material.

The disclosed flexible vibrotactile devices may include a dielectric support material, at least one flexible electroactive element coupled to the dielectric support material, a first conductive electrode material, and a second conductive electrode material. The dielectric support material may include at least one hole therethrough for securing the flexible vibrotactile device to a textile by threading at least one fiber through the at least one hole. Various other related methods and systems are also disclosed.

Aspects include piezoelectric acoustic transducers and systems for acoustic transduction. In some aspects, an acoustic transducer is structured with a silicon substrate having a top surface and a bottom surface, where the top surface has a first portion and an edge along the first portion associated with an acoustic aperture. The transducer has a first silicon oxide layer disposed over the first portion of the top surface of the silicon substrate, a polysilicon layer disposed over the first silicon oxide layer, and a second silicon oxide layer disposed over the polysilicon layer. A cantilevered beam comprising a fixed end, a deflection end, a top surface, and a bottom surface, has a first portion of the bottom surface at the fixed end disposed over the second silicon oxide layer, where a second portion of the bottom surface at the deflection end is formed over the acoustic aperture. In some aspects. transducer elements are reconfigurable between parallel and serial configurations depending on a system operating mode.