343 results about "Piezoelectric membrane" patented technology

A piezoelectric element includes a first electrode, a piezoelectric film disposed on the first electrode, and a second electrode disposed on the piezoelectric film. The piezoelectric film is composed of piezoelectric material that is lead free and formed by mixing 100(1−x)% of material A having a spontaneous polarization of 0.5 C/m2 or greater at 25° C. and 100 x % of material B having piezoelectric characteristics and a dielectric constant of 1000 or greater at 25° C., wherein (1−x)Tc(A)+xTc(B)≧300° C., where Tc(A) is the Curie temperature of the material A and Tc(B) is the Curie temperature of the material B.

Vibration transmitting apparatus comprises a vibrating element utilizing a piezoelectric membrane element installed within a bio-compatible sealed case, wherein one end of the piezoelectric element is in static positioned relationship with respect to its casing and the other end is free to move and to vibrate.

Micromachined ultrasonic transducer (MUT) arrays capable of multiple resonant modes and techniques for operating them are described, for example to achieve both high frequency and low frequency operation in a same device. In embodiments, various sizes of piezoelectric membranes are fabricated for tuning resonance frequency across the membranes. The variously sized piezoelectric membranes are gradually transitioned across a length of the substrate to mitigate destructive interference between membranes oscillating in different modes and frequencies.

The invention provides a piezoelectric ultrasonic transducer and a manufacturing method thereof. The piezoelectric ultrasonic transducer comprises a base, a vibrating membrane, a first electrode, a piezoelectric membrane and a second electrode, wherein the center of the base is provided with a cavity; the vibrating membrane is fixed to the base; the first electrode, the piezoelectric membrane and the second electrode are sequentially deposited on the vibrating membrane along a direction from the base to the vibrating membrane; the piezoelectric ultrasonic transducer is characterized in that the vibrating membrane comprises a first vibrating membrane and a second vibrating membrane, wherein the first vibrating membrane is positioned at the center; the second vibrating membrane is positioned at the outer side of the first vibrating membrane; the first vibrating membrane and the second vibrating membrane are arranged in a spaced manner and are connected with each other through an elastic structure layer; and the piezoelectric ultrasonic transducer is also provided with a through hole at a position corresponding to the elastic structure layer, wherein the through hole penetrates through the second electrode, the piezoelectric membrane and the first electrode. The piezoelectric ultrasonic transducer provided by the invention can improve output of sound pressure.

Disclosed is a transparent piezoelectric sheet with a frame, which has a wider effective area, is capable of more accurate touch pressure recognition, and has low manufacturing cost and a pleasing appearance. The piezoelectric sheet with a frame comprises one transparent piezoelectric membrane containing an organic polymer, one first transparent flat-plate electrode disposed to a first principal surface of the transparent piezoelectric membrane, and one second transparent flat-plate electrode disposed to a second principal surface of the transparent piezoelectric membrane. The first transparent flat-plate electrode includes a first transparent flat-plate electrode section, and the second transparent flat-plate electrode includes a second transparent flat-plate electrode section. The outline of the second transparent electrode section includes a transparent piezoelectric sheet, which when seen in plan view is positioned inside the outline of the first transparent flat-plate electrode section, and a frame covering the periphery of the transparent piezoelectric sheet. The outline of the first transparent flat-plate electrode section when seen in plan view overlaps the whole of the frame, and the outline of the second transparent flat-plate electrode section does not overlap the frame at all.

The invention discloses a muscle tension sensor and a muscle tension detecting method. The muscle tension sensor is characterized in that: a box body and a bottom end cover form a cylindrical shell; in the cylindrical shell, a pressure sensor is adhered with the top plate of the box body, a 'T'-shaped probe is pressed against the bottom end face of the pressure sensor by the top end face, a raisecylinder on the 'T'-shaped probe runs through a central hole in the bottom end cover and protrudes to the outside of the cylindrical shell; outside the cylindrical shell, a piezoelectric membrane resistor serving as a piezoelectric device is adhered with the top plate of the box body; above the box body, another 'T'-shaped top cover is pressed against the piezoelectric membrane resistor by the bottom end face; and above the top cover, a pressure plate and a top cover form a clamp plate, and a band is clamped in the clamp plate formed by the pressure plate and the top cover. When the sensor and the method are used, muscle tension parameters can be acquired stably and used for evaluating the recovery state of muscle after rehabilitation of a human body.

The invention relates to a soft support bridge type silicon micro-piezoelectric ultrasonic transducer chip which comprises a silicon substrate with a square conical hole which is small at the top andbig at the bottom in the center; a silicon layer and a first oxidation layer are sequentially covered on the front surface of the silicon substrate, and a second oxidation layer is covered on the backsurface; the corresponding silicon layer and the first oxidation layer above the square hole of the front surface of the silicon substrate constitute a square vibration membrane, one pair of oppositesides of the square vibration membrane respectively etch a vertical narrow slot, and the vertical projection of each narrow slot is positioned on the inner side of the hole edge above the front surface of the silicon substrate; a lower electrode, a piezoelectric membrane and an upper electrode are sequentially deposited on the square vibration membrane; a polyimide membrane is deposited on various parts on the front surface of the silicon substrate; and the square vibration membrane which is etched with the vertical narrow slots and the polyimide membrane commonly constitute a soft support anti-sound leakage bridge type vibration membrane. The anti-sound leakage bridge type structure is used on the vibration membrane of the transducer; in order to avoid sound leakage through the narrow slots, the soft polyimide membrane is deposited on the narrow slots, which has little effect on vibration of the vibration membrane and can still keep high sensitivity.

A method for producing a porous piezoelectric polymer film with a dense surface, includes depositing a polymer solution onto a substrate to form a polymer film including a solvent; evaporating a portion of the solvent to form the dense surface away from the substrate; forming water droplets in interior of the polymer film; and substantially evaporating the water droplets and remaining solvent to form porous interior. A piezoelectric composition includes a piezoelectric material with a porous interior and a dense surface for interfacing with an electrode. A piezoelectric device includes a first electrode; a porous piezoelectric film with a dense surface and porous interior, wherein the porous piezoelectric film is deposited on the first electrode and the dense surface is away from the first electrode; and a second electrode deposited on the dense surface for, together with the first electrode, providing an electrical interface for the porous piezoelectric film.

A piezoelectric element includes a first electrode; a piezoelectric layered film composed of a first piezoelectric film formed on the first electrode film and a second piezoelectric film that is formed on the first piezoelectric film and is controlled in crystal orientation thereof by the first piezoelectric film; and a second electrode film formed on the second piezoelectric film. Each of the first and second piezoelectric films is an aggregate of columnar grains grown unidirectionally along a thickness direction of the piezoelectric layered film. A columnar grain of the second piezoelectric film has a larger cross-sectional diameter than a columnar grain of the first piezoelectric film. A ratio l/d of the thickness l of the piezoelectric layered film to the cross-sectional diameter d of the second piezoelectric film is not less than 20 and not more than 60.

A piezoelectric device includes a first electrode film, a piezoelectric film disposed on the first electrode film, and a second electrode film disposed on the piezoelectric film. At least one of the first and second electrode films is composed of an alloy, and a main component of the alloy is a metal selected from the group consisting of Ti, Al, Mg, and Zn. The piezoelectric film has a main composition represented by (K_1-x-y-w-vNa_xLi_yBa_wSr_v)_m(Nb_1-z-uTa_zZr_u)O₃ (1), where x, y, z, w, v, u, and m in formula (1) satisfy 0.4<x≦0.7, 0.02≦y≦0.11, 0.5≦x+y<0.75, 0<z≦0.28, 0<w≦0.02, 0.02≦v≦0.11, 0.02≦u≦0.11, and 0.95≦m<1.2, and contains 1% by mass or less of MnO relative to the main composition.

The invention discloses a closed loop piezoelectric membrane pump and a flow control method thereof. The closed loop piezoelectric membrane pump comprises a piezoelectric vibrator, a flow sensor, a piezoelectric pump basal body, a circuit control module, a liquid inlet valve and a liquid outlet valve, wherein the liquid inlet valve and the liquid outlet valve are used for controlling the motion direction of fluid; the piezoelectric pump basal body is provided with a pipeline and a pump cavity formed in the piezoelectric pump basal body; the piezoelectric vibrator, the liquid inlet valve and the liquid outlet valve are all mounted on the piezoelectric pump basal body; the flow sensor and the piezoelectric pump basal body are integrated into a whole structure; a flow filter is arranged between a microchannel and the liquid outlet valve; the fluid uniformly flows into the flow sensor through controlling the pressure of the fluid by the flow filter. The closed loop piezoelectric membrane pump is small in size, high in precision of driving the fluid, and good in machinability and consistency.

A filter includes one or a plurality of parallel resonators coupled in parallel and one or a plurality of a film bulk acoustic resonators coupled in series, the film bulk acoustic resonator having a substrate, a lower electrode, a piezoelectric membrane, and an upper electrode, wherein: at least one of the lower electrode and the upper electrode has a thick membrane region having a thickness larger than that of a center portion of a resonance region at an edge of the resonance region, the resonance region being a region where the lower electrode and the upper electrode face with each other through the piezoelectric membrane; and a width of the thick membrane region is smaller than a wavelength of an acoustic wave propagating in a direction crossing a thickness direction of the piezoelectric membrane.

A liquid ejecting head which includes a piezoelectric element which includes a first electrode, a piezoelectric layer which is provided on the first electrode, and on which a plurality of piezoelectric films are laminated, a second electrode which is provided on the piezoelectric layer, and a plurality of active units which are interposed between the first electrode and the second electrode, and a pressure generating chamber which communicates with nozzle openings which eject liquid, and in which a pressure fluctuation is generated by the piezoelectric element, in which a plurality of grooves with inner faces facing the first electrode side are formed on a side surface of the piezoelectric layer on each interface of each of the piezoelectric films along a first direction and a second direction which cross a third direction which goes from the first electrode to the second electrode.

A piezoelectric device, including the following on a substrate in the order listed below: a lower electrode, a piezoelectric film which contains a Pb containing perovskite oxide represented by a general expression (P) below, and an upper electrode, in which the piezoelectric film has a layer of pyrochlore oxide on the surface facing the lower electrode, and the average layer thickness of the pyrochlore oxide layer is not greater than 20 nm.

A_aB_bO₃  (P)

where, A: at least one type of A-site element containing Pb as a major component, B: at least one type of B-site element selected from the group consisting of Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Sc, Co, Cu, In, Sn, Ga, Zn, Cd, Fe, and Ni, and O: an oxygen element.

In a method for etching a piezoelectric film and a manufacturing method thereof, a piezoelectric film is formed on a substrate on which a lower electrode is formed, a metal film having a thickness of 20 nm to 300 nm is formed, a patterned resist film is formed, the metal film is etched with a first etchant to which the piezoelectric film has etching resistance, and the piezoelectric film is etched with a second etchant to which the metal film has etching resistance.

The invention relates to a silicon micro piezoelectric sensor chip, which comprises: big-end-down square-pyramid holes on center of N-type silicon substrate, a deposited silicon nitride base film layer and mask layer on front and reverse surface of substrate, a circular hole on center of base film layer, a square hole on mask layer center with same size as the one on silicon substrate reverse surface, a silicon nitride vibration film on top surface of base film layer with circular upper electrode and lower electrode that has circular piezoelectric film on its top surface with circular low-temperature silicon oxide film protection layer by photo etching. Wherein, the silicon nitride or multicrystal silicon vibration film and piezoelectric film form circular piezoelectric film/ silicon nitride or multicrystal silicon composite bending vibration film. This invention can reduce the unevenness of vibration stress to prevent film breakage, and improves sensitivity of sensor.

A piezoelectric device according to the present invention is provided with a first electrode film, a first nonmetal electroconductive intermediate film provided on the first electrode film, a piezoelectric film provided on the first nonmetal electroconductive intermediate film, a second nonmetal electroconductive intermediate film provided on the piezoelectric film, and a second electrode film provided on the second nonmetal electroconductive intermediate film. A linear expansion coefficient of the first nonmetal electroconductive intermediate film is larger than those of the first electrode film and the piezoelectric film, and a linear expansion coefficient of the second nonmetal electroconductive intermediate film is larger than those of the second electrode film and the piezoelectric film.

The invention relates to the technical field of micro-electronics technique and a device thereof, in particular to a preparation method of a novel piezoelectric membrane resonator. The invention is characterized in that an SOI wafer is adopted to etch a plurality of etch baths or etch pits on a top layer of silicon; then hydrofluoric acid is used for etching an insulating layer in the surrounded range among the baths or pits; a suspended silicon layer is formed on the top layer of the wafer; next, a bottom electrode material, a piezoelectric membrane material and a top electrode material are deposited on the suspended top layer of silicon in sequence so as to form the piezoelectric membrane resonator. The invention has the beneficial effects that the SOI wafer is adopted to manufacture a cavity-typed piezoelectric membrane resonator; wherein, an oxide layer between two layers of silicon is used as a sacrificial layer, thus saving the step of depositing the sacrificial layer and simplifying the technique; besides, the sacrificial layer is compatible with the silicon technique, therefore, a resonator array and an external circuit are integrated so as to lead the circuit to has the advantages of high speed, low voltage, low power consumption, high sensitivity, fast response speed and multiple channels and simultaneously lead the device to have higher degree of micromation and integration.

The invention relates to a polyvinylidene fluoride fiber array piezoelectric membrane and a preparation method of the polyvinylidene fluoride fiber array piezoelectric membrane, and belongs to preparation technologies of piezoelectric materials. The polyvinylidene fluoride fiber array piezoelectric membrane is formed by equal-length fibers which are closely arranged in an orientation mode, the diameter of each fiber is 30nm-500nm, and the thickness of the polyvinylidene fluoride fiber array piezoelectric membrane is 50microns-1000microns. The preparation method of the polyvinylidene fluoride fiber array piezoelectric membrane comprises the steps of preparing fiber bundles of highly-oriented arrangement through an electrostatic spinning polyvinylidene fluoride solution, manufacturing the fiber bundles into compact fiber bundle sticks, slicing the fiber bundle sticks, and obtaining the polyvinylidene fluoride fiber array piezoelectric membrane. The polyvinylidene fluoride fiber array piezoelectric membrane and the preparation method of the polyvinylidene fluoride fiber array piezoelectric membrane aim at overcoming the defect that high beta crystal phase transition and beta crystal phase orderly orientation arrangement cannot be achieved in an existing polyvinylidene fluoride piezoelectric membrane preparation technology. The preparation method of the polyvinylidene fluoride fiber array piezoelectric membrane is simple in operation, and achieves synchronous conduct of the high beta crystal phase transition and the beta crystal phase orderly orientation arrangement of polyvinylidene fluoride, the prepared polyvinylidene fluoride fiber array piezoelectric membrane has a high piezoelectric constant and an energy conversion coefficient, and each fiber is a piezoelectric generator.