191 results about "Polarization density" patented technology

An interdigitated electrode ferroic transducer includes a film of ferroic material electrically polarized substantially in the plane of the film; and a set of interdigitated electrodes including at least two electrodes spaced from one another on the same side of the film and disposed at the termini of the polarization field.

The present invention provides a film LED chip device basing on the combined low-resistance buffer structure and the manufacturing method thereof, the insulating buffer film is packaged on side wall of all metal structures and is filled in all non-electrical connected areas, with filling in insulating buffer film between all metal convex points which connects the GaN base illuminating device and the electric polarized substrate, the filling-in thickness is a little under or even with the height of the metallic convex points, and with directly liking the GaN base illuminating device crystal disc with the whole surface of the electric polarized inversely mounted substrate with the mode of whole surface linking of the wafer, the metallic convex point of the conductive supporting thick metal layer and the insulating buffer film form the combined low-resistance buffer structure of the invention together, not only the electric connection between the GaN base illuminating device and the electric polarized inversely mounted substrate is realized, but also the buffer layer filling is realized thereby reducing the wafer rupture incidence rate of the subsequent laser stripping technique in order to increase the good product ratio, besides the stripped sapphire substrate disc which can execute finishing to the sapphire substrate and is obtained after stripped operation can be recovered for reusing, the production cost is reduced.

There is a need for methods that can produce piezoelectric composites having suitable physical characteristics and also optimized electrical stimulatory properties. The present application provides piezoelectric composites, including tissue-stimulating composites, as well as methods of making such composites, that meet these needs. In embodiments, methods of making a spinal implant are provided. The methods suitably comprise preparing a thermoset, thermoplastic or thermoset/thermoplastic, or copolymer polymerizable matrix, dispersing a plurality of piezoelectric particles in the polymerizable matrix to generate dispersion, shaping the dispersion, inducing an electric polarization in the piezoelectric particles in the shaped dispersion, wherein at least 40% of the piezoelectric particles form chains.

The invention discloses a one-phase ferroelectric film capable of regulating effective resistance by ferroelectric polarization, a preparing method of the one-phase ferroelectric film and an effective resistance regulation mode. The one-phase ferroelectric film comprises B-bit-doped Bal-xSrxTil-yByO3, Pb(Fe1-yBy)O3, Pb(Co1-yBy)O3, (Pb1-xAx)(ZryTi1-y)O3, A-bit-doped Y1-xAxMnO3, Bil-xAxFeO3, and Bi4-xAxTi3O12. The one-phase ferroelectric film is prepared by using film preparing methods, such as pulsed laser deposition (PLD), laser molecular beam epitaxy (LMBE) and magnetron sputtering. The prepared ferroelectric film is 0.4-1000 nanometer in the thickness and has larger conductance and leakage current, as well as ferroelectricity and semiconductor performance. The invention provides a method for improving the antifatigue performance of the one-phase ferroelectric film. Turning frequency (x) of the ferroelectric polarization in the method can be increased to 102-1010; and the ferroelectric polarization is turned to regulate the effective resistance of the one-phase ferroelectric film.

The invention relates to a magnetic recording medium based on a multiferroic film, comprising a substrate and a medium layer growing on the substrate. The medium is characterized in that the medium layer comprises a ferroelectric structure unit formed by a ferroelectric material and a ferromagnetic structure unit formed by a ferromagnetic material. The write-in method comprises the following steps: an electric signal generated by a signal source is applied to two ends of the ferroelectric structure unit; an impulse voltage signal generated by the signal source changes the polarized state of a ferroelectric layer; through a magnetoelectric coupling effect, changes of the polarized state can further change the magnetization direction in the ferroelectric structure unit so as to record the state of an electric signal and complete information storage. Compared with the prior art, the invention provides the novel magnetic recording medium of the multiferroic composite material and several structures for recording the medium based on the traditional magnetic recording medium; and the medium using the multiferroic materials for recording can realize the magnetic recording method for electric write-in, and has wide application prospect for novel multifunctional devices with high density storage.

A method for producing transducers having a 1-3 composite structure. The transducer element includes a plurality of thin piezoceramic wafers which are electroded on opposing major surfaces. The spaced wafers are separated by a passive polymer layer in a composite structure and the electrodes on the opposing major surfaces are connected to different ones of top and bottom electrode surfaces.

The present invention generally relates to nanotechnology and submicroelectronic devices that can be used in circuitry and, in some cases, to nanoscale wires and other nanostructures able to encode data. One aspect of the invention provides a nanoscale wire or other nanostructure having a region that is electrically-polarizable, for example, a nanoscale wire may comprise a core and an electrically-polarizable shell. In some cases, the electrically-polarizable region is able to retain its polarization state in the absence of an external electric field. All, or only a portion, of the electricallypolarizable region may be polarized, for example, to encode one or more bits of data. In one set of embodiments, the electrically-polarizable region comprises a functional oxide or a ferroelectric oxide material, for example, BaTiO₃, lead zirconium titanate, or the like. In some embodiments, the nanoscale wire (or other nanostructure) may further comprise other materials, for example, a separation region separating the electricallypolarizable region from other regions of the nanoscale wire. For example, in a nanoscale wire, one or more intermediate shells may separate the core from the electricallypolarizable shell.

The invention relates to a system and a method for testing magnetoelectricity property of a multiferroic thin-film material, belonging to the field of property tests of materials. The system is characterized by comprising a DC bias magnetic field generating device, an AC magnetic field generating device, a thin-film sample probe holding device and a micro signal acquiring and amplifying device. The invention also provides a method for testing magnetoelectricity property of the multiferroic thin-film material. The invention can recognize the difference of an electromagnetic inductive interference signal and a multiferroic magnetoelectricity responding signal by accurately testing a thin-film micro electric responding signal so as to obtain a real amplitude of a magnetoelectricity coefficient of the multiferroic thin-film material under different frequencies and bias magnetic fields and also obtain the change law of thin-film sample polarization with an alternating magnetic field.

The invention discloses a method for manufacturing a high-electrical-property nano generator based on a piezoelectric-frictional effect. The small-area high-output-voltage nano generator is manufactured on the basis of the piezoelectric effect and the frictional effect. According to the method, CNT particles and piezoelectric particles in a certain proportion are mixed into liquid PDMS to be manufactured into a composite film, a micro-nano concave-convex structure with rules is manufactured on the surface of the composite film through a micro-processing method, finally electric polarization is carried out on the composite film, and an electrode is arranged in a clamping mode. The method combines the advantages of piezoelectricity and friction, and the manufactured piezoelectric-frictional nano generator with the small area, high sensitivity and high voltage output is low in manufacturing cost and simple in process, has good durability and workability, enables large-scale production and application to be carried out conveniently, and can be easily blended in the design of other products. Self-powered and self-driven equipment is provided for personnel electronic products, environmental monitoring, medical science and the like, and huge commercial and practical potentials are achieved.

The invention provides a method for detecting the service life of a cable. The method is used for detecting the service life of the cable respectively in three different detection ways as follows: measuring an isothermal relaxation current in a cable depolarization process, and calculating an aging factor to obtain a first service life value; carrying out thermal aging treatment on a cable sample, and measuring the thermal aging failure time and the corresponding aging temperature to obtain a second service life value of the measured cable under the rated working temperature; applying a breakdown voltage to the measured cable to obtain a third service life value; and accurately determining the average service life of the measured cable according to the three measured service life values. As the influence of electric polarization, thermal aging and voltage breakdown on the service life of the cable is respectively considered by parameters involved in detection, the measured service life of the cable is more accurate.

A normally-off type field-controlled channel GaN heterojunction diode belongs to the technical field of semiconductor devices. The invention adopts the technology of combining insulating layer-groove, modulation doping and groove-modulation doping to change the conductive channel structure of the existing GaN heterojunction diode, and convert the original normally-on spontaneously polarized GaN heterojunction The junction conductive channel is changed into a normally-off field-controlled conductive channel combining spontaneous polarization and piezoelectric polarization in the present invention, which realizes the field-controlled characteristics of the GaN heterojunction diode conductive channel and reduces the forward conduction resistance and enhanced reverse cut-off capability. The invention has lower forward conduction resistance and power consumption, stronger reverse cut-off ability, and is compatible with AlGaN/GaN HEMT power switching device technology, which is beneficial to the application of the device.

The invention is related to a climate control system with one dimmable device capable of variably reducing the transmission of radiation through a window, and a climate control unit coupled to and adapted to control the dimmable device. The dimmable device includes at least one inherent conductive polymer and at least one ionic liquid. The dimmable device is controlled to change colours and/or dimming levels by applying a voltage pulse of a first electrical polarisation for darkening and a second reverse polarized voltage pulse for bleaching.

A method and device for generating terahertz radiation comprising a polar crystal material layer operative to emit terahertz radiation; the polar crystal material layer comprising a plurality of stacking faults; the stacking faults lying substantially perpendicular to the polar axis and forming boundaries at which the internal electric polarization terminates leading to charges accumulating at the boundaries, and creation of internal electric fields oriented along the polar axis; a pulsed radiation source for creating photogenerated carriers in the polar crystal material; whereby the photogenerated carriers accelerate in the internal electric fields associated with the termination of the internal electric polarization by the stacking faults to thereby generate terahertz radiation.

The invention discloses an irradiation-modified polyurethane piezoelectric damping material with a conductive channel prepared from graphene and a preparation method for the same. The method comprises the following steps of: (1) mixing polyether ester polyol, 4,4'-dicyclohexyl methylene diphenyl diisocyanate, a catalyst, graphene, piezoelectric ceramic powder, dioxethyl butynediol and 1,4-butanediol to obtain a mixed material, performing vacuum defoaming on the mixed material, then pouring the mixed material in a mould, and sheeting via tape-casting to obtain sheets; (2) thermally curing the sheets, and then performing vacuum mould pressing to obtain a plate; and (3) irradiating the plate, and then performing electric polarization treatment to obtain the product. According to the method disclosed by the invention, via the introduction of the graphene conductive channel, the dielectric constant of the material is greatly increased, and the damping performance of the material is greatly improved. According to the method disclosed by the invention, crosslinking treatment is performed on the material via irradiation, so that the mechanical performance of the material is improved under the action of irradiation; and simultaneously, the post-curing time of the material is reduced, the production process is simplified, and the damping performance of the material is good.

The invention provides construction and preparation of a three-dimensional bionic electropolarized gradient pore nerve conduit. The nerve conduit is an electropolarized beta-tricalcium phosphate/polylactic acid/hyaluronic acid/chitosan/nerve growth factor nerve conduit, and is prepared by the steps of: preparing a uniformly dispersed electropolarized beta-tricalcium phosphate and polylactic acid core material by using polylactic acid as a substrate material and adding the electropolarized beta-tricalcium phosphate; and preparing a three-dimensional bionic electropolarized gradient pore nerve conduit with component and pore structure double gradient by attaching the hyaluronic acid, the chitosan and the nerve growth factor to the surface of the core material by virtue of electrostatic self-assembly and coupling crosslinking, wherein the length is between 10 and 100mm, the inner diameter is between 1 and 6mm, the wall thickness is between 0.5 and 2mm, and the outer tube wall is of a three-dimensional network structure. The nerve conduit is applied to repairing of a peripheral nervous system, induction of peripheral nerve regeneration and in-vitro culture of nerve cells in tissue engineering. The three-dimensional bionic electropolarized gradient pore nerve conduit has the advantages of simple preparation method, low cost, environmental friendliness and high economical benefit, and is applicable to industrial production.

The invention discloses a terahertz GaN Gunn diode based on an SiC substrate and a manufacturing method thereof, which are used for mainly solving the problems of low output power, poor heat radiation performance and the like in the traditional Gunn device structure. The diode respectively comprises the SiC substrate, an AlN nucleating layer, an n+GaN ohmic contact layer, an electron emitting layer, an n-GaN active layer and an n+GaN ohmic contact layer from bottom to top and is characterized in that the electron emitting layer is made of an InAlN material with 14-22% of an In component and has the thickness of 80-200 nm; a through hole (1) is etched in the SiC substrate; metals Ti/Al/Ni/Au are deposited at the bottom of the substrate; and the metals are connected with an annular electrode (5) through the through hole, so that a longitudinal device structure is formed. The terahertz GaN Gunn diode disclosed by the invention is capable of eliminating a piezoelectric polarization effect and obviously reducing interface dislocation and the length of a Dead Zone, has the advantages of high output power and working frequency, and is applied to working in terahertz frequency bands.

The present invention relates to a structure of a solar cell for improving photoelectric conversion efficiency of the solar cell, and a manufacturing method therefor. One aspect of the solar cell according to the present invention relates to a solar cell having a light-absorbing layer formed between two electrodes arranged to face each other, wherein an electrical polarization layer comprising an electrical polarization material forming an inner electrical field is formed between the electrodes and the light-absorbing layer.

The invention discloses a magneto-electric coupling ceramics material. Its chemical formula is (Bi1-xAxFe1-yByO3), and 0<=x<0.5, 0<=y<0.2, x, y can not equal 0 in the same time. an is trivalency rare earth metal ion selected one or two kinds from La, Nd, Td, Sm and Pr. B is a transition metal ion Mn or Co. The material has following physical property: breakdown electric field is over 150kV/ cm, its breakdown electric field is between 3 microcoulomb per square centimeter to 30 microcoulomb per square centimeter. Meanwhile, the invention discloses the method to produce the material. Its feature is when sintering, temperature would increase at the speed of 30 degree per second and stabilizing between 850 degree centigrade and 940 degree centigrade, then cooling quickly.

A method for in situ monitoring of a membrane of a membrane separation system comprises measuring a complex impedance of the membrane at a plurality of frequencies to provide an indication of the electrical conduction and electrical polarization properties of the membrane. The membrane based separation system for removing or reducing the concentration of materials carried in a fluid including a separation membrane has a first pair of electrodes separated by the membrane and arranged for measurement of the complex impedance of the membrane at a plurality of frequencies to provide the indication of the membrane properties. There may also be a second pair of electrodes separated by the membrane for injecting the stimulus current such that the injecting and monitoring functions are separated.

The invention provides a single-phase oxide multiferroic ceramic with exchange bias effect. The single-phase oxide multiferroic ceramic is as shown in the formula (I): Bi10Fe5.9Co0.1Ti3O30 (I). The single-phase oxide multiferroic ceramic has high Curie temperature, has ferroelectricity and ferromagnetism under the room temperature at the same time, and has intrinsic exchange bias effect. Not only a magnetic field can be regulated and controlled, but also an electric field can be regulated and controlled, the possibility of encoding storage information through the adoption of electric polarization and magnetic polarization at the same is provided, and then a magneto-electric mutual-control nonvolatile storage magnetic medium with ultrahigh storage density becomes possible.

An optical detector has the following strain alloplasm materials on the silicon or sapphire gemstone substrate: with AIN as the buffer layer strain alloplasm structure GAN is grown extendedly. Polarized electric field arisen from the self-piezoelectric polarization effect especially for the strain alloplasm structure can effectively separate optical-electron-cavity couple to lower the direct complex lose to increase the lift of optical-carrier. Alloying metal electrode extends to the inner part of GAN from surface to reduce the surface complex loss of the carrier to raise the collective efficiency.

A method for enhancement of thermoelectric properties through polarization engineering. Internal electric fields created within a material are used to spatially confine electrons for the purpose of enhancing thermoelectric properties. Electric fields can be induced within a material by the presence of bound charges at interfaces. A combination of spontaneous and piezoelectric polarization can induce this interfacial charge. The fields created by these bound charges have the effect of confining charge carriers near these interfaces. By confining charge carriers to a channel where scattering centers can be deliberately excluded the electron mobility can be enhanced, thus enhancing thermoelectric power factor. Simultaneously, phonons will not be affected by the fields and thus will be subject to the many scattering centers present in the majority of the structure. This allows for simultaneous enhancement of power factor and reduction of thermal conductivity, thus improving the thermoelectric figure of merit, ZT. This approach is also compatible with other strategies for reducing thermal conductivity, for example the inclusion of nanostructures.