132results about "Device material selection" patented technology

The invention discloses a triple system (Na,Bi)TiO3-based lead-free piezoelectric ceramic material, the formula of the disclosed lead-free piezoelectric ceramic component is denoted with (1-x-y)(Bi0.5Na0.5)TiO3-x(Bi0.5K0.5)TiO3-yBi(Me)O3 and (1-x-y)(Bi0.5Na0.5)TiO3-x(Bi0.5K0.5)TiO-yBi(Me)O3+zM(a)O(b), in the formula x,y and z denote molar fractions, wherein x is bigger than or equal to 0 and smaller than or equal to 1.0, y is bigger than or equal to 0 and smaller than or equal to 0.2, z is bigger than or equal to 0 and smaller than or equal to 0.1, Me is trivalent metal element, M(a)O(b) is one or more oxides, wherein M is +1 to +6 valence and is an element that can be integrated with oxygen to form a solid oxide. The lead-free piezoelectric ceramic has high ceramic density and excellent performance, piezoelectric constant d33 can reach above 180pC per N, Kp can reach above 0.36. The lead-free piezoelectric ceramic adopts traditional electronic ceramic preparation process, and has low sintering temperature, simple and stable manufacture process and is suitable for industrialization production.

The invention discloses a multi-element piezoelectric composite material and a preparation method. The multi-element piezoelectric composite material is a 1-3-2 type composite material consisting of a piezoelectric ceramic/ polymer composite material and a decoupling material, wherein the piezoelectric ceramic/ polymer composite material takes piezoelectric ceramic as a skeleton and a polymer as a base body and is attached with an upper electrode and a lower electrode, the piezoelectric ceramic skeleton comprises a substrate and a piezoelectric ceramic column connected to the substrate, the decoupling material is filled in the piezoelectric ceramic/ polymer composite material, the piezoelectric ceramic/ polymer composite material is divided into a plurality of units of the same structure by the decoupling material, and the upper electrodes of all elements are discontinuous. Through the adding of the decoupling material, the whole composite material is divided into a plurality of units. The preparation technology is simple. The obtained multi-element material has excellent property, good consistency, low coupling and wide application prospect in the field of transducers.

The present invention provides a piezoelectric composite sensor comprising a piezoelectric material layer formed of a piezoelectric composite obtained by mixing piezoelectric material powder with a polymer, and electrodes formed of a conductive composite or conductive polymer obtained by mixing conductive filling particles with a polymer matrix and formed on both surfaces of the piezoelectric material layer. The piezoelectric composite sensor of the present invention has advantages of superior piezoelectric and dielectric properties, high mechanical strength, improved reliability and process flexibility, a simplified process and reduced process costs, and improved productivity.

A piezoelectric planar composite apparatus to provide health monitoring of a structure and associated methods are provided. The piezoelectric planar composite apparatus includes a piezoelectric electric material layer, multiple electrodes positioned in electrical contact with the piezoelectric material layer, and multiple sets of electrode interconnect conductors each positioned in electrical contact with a different subset of the of the electrodes and positioned to form multiple complementary electrode patterns. Each of the complementary electrode patterns is positioned to form an electric field having an electric field axis oriented along a different physical axis from that of an electric field formed by at least one other of the complementary electrode patterns. The interconnect conductors can be distributed over several electrode interconnect conductor carrying layers to enhance formation of the different complementary electrode patterns.

The invention relates to a film magnetoelectric composite material and a preparation method thereof, and belongs to the technical field of magnetic functional materials and preparation thereof. The magnetoelectric composite material is characterized by being prepared by compounding a magnetostrictive film layer, a conductive film layer and a piezoelectric ceramic substrate. In the preparation method, the magnetostrictive film layer is deposited on the piezoelectric substrate with a prepared electrode by physical vapor deposition (PVD) technology. The magnetoelectric composite material has high interfacial composite strength, a simple structure, a high magnetoelectric conversion coefficient, low high-frequency eddy current loss, stable performance and thin and light size, effectively avoids phase reaction between ferroelectric and ferromagnetic phases, and is particularly suitable for preparing a micro sensor; in addition, the preparation method is simple and feasible, and low in cost, and overcomes the defects of a complicated preparation process, high cost and the like of a laminated magnetoelectric composite material and the conventional film magnetoelectric composite material.

Energy harvesting elements or membranes are provided that use a layer of electrodes with a mixture of carbon nanotubes (CNT). The energy harvesting device of this type can be used as in sensor-based system in which on application of a bending load, the energy harvesting device produces a voltage across the electrodes. The energy harvesting device may include an electrode coating including carbon nanotubes (CNT) substantially homogenously dispersed in epoxy resin system to form a CNT-epoxy electrode coating. The CNT-epoxy electrode can be realized by dispersing about 5% CNT (by weight) in an epoxy-resin system, followed by mixing the system to achieve a near-homogenous dispersion resulting in a CNT-epoxy mixture. The CNT-epoxy mixture can then be uniformly coated on surfaces of a polymer to form electrodes.

Existing magnetoelectric materials relying on the use of metallic or ceramic magnetostrictive materials and ceramic piezoelectric materials as their constituent phases may have three problems. First, the operational frequency may be limited to a few kilohertz due to the presence of eddy-current losses in the metallic magnetostrictive phase. Secondly, it may be difficult to machine and fabricate devices due to the mechanical brittleness of the ceramic and some metallic magnetostrictive phases as well as of the ceramic piezoelectric phase. Thirdly, it may be difficult to tailor and optimize the properties (i.e., magnetoelectric voltage coefficient α_E, etc.) of the devices due to the limitation of the types of the constituent materials. This invention provides a magnetoelectric element including at least one set of alternative piezoelectric layer and magnetostrictive composite layer. The magnetostrictive composite layer includes at least one magnetostrictive material dispersed in first concentrated zones within a first polymer matrix, wherein all of said concentrated zones are orientated along a first direction. It is found that the conversion efficiency (i.e., α_E) varies in accordance with applied magnetic control field H_control in magnetoelectric devices made of such a magnetoelectric element.

The magnetoelectricity composite material is a rectangle piece (1) divided into two areas A1 and A2 along longitudinal direction. A1 is made from magnetostrictive material, and A2 is made from piezodielectric material. A1 and A2 are combined through agglomerant. A pair of flat pole (4a and 4b) is in the A2 area. The piezodielectric material is polarized along thick direction. The said magnetostrictive material is magnetostrictive alloy, oxide or their composite material with polymer. The said piezodielectric material is piezoelectric ceramic or a composite material formed from piezoelectric ceramic and polymer. When dc magnetic biasing field and AC magnetic field with small signal are applied to rectangle piece 2 of magnetostrictive material along longitudinal direction, the rectangle piece (1) of magnetoelectricity generates resonance near to 60kHz, and voltage is output through rectangle piece 3 of piezodielectric composite material so as to realize magneto-electric coupling.

There is provided a piezoelectric/electrostrictive porcelain composition capable of manufacturing a piezoelectric/electrostrictive article or a piezoelectric/electrostrictive portion which exhibits superior piezoelectric/electrostrictive characteristics without containing lead (Pb). The piezoelectric/electrostrictive porcelain composition contains as a main component a binary solid solution represented by the general formula (1): €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ (1-n)(Ag 1-a-b-c Li a Na b K c ) (Nb 1-x-y-z Ta x Sb y V z O 3 + nM 1 M 2 O 3 wherein 0 ‰¤ a ‰¤ 0.2, 0 ‰¤ b ‰¤ 0.95, 0 ‰¤ c ‰¤ 0.95, 0 < (1 - a - b - c) ‰¤ 1, 0 ‰¤ x ‰¤ 0.5, 0 ‰¤ y ‰¤ 0.2, 0 ‰¤ z ‰¤ 0.2, 0 ‰¤ (y+z) ‰¤ 0.3, 0 ‰¤ n ‰¤ 0.2, wherein in the general formula (1), M 1 and M 2 are combinations of metal elements which satisfy predetermined conditions.

A piezoelectric thin film element that includes a substrate, a lower electrode on the substrate, a piezoelectric film on the lower electrode, and an upper electrode on the piezoelectric film. The piezoelectric film is a potassium sodium niobate film represented, as its main constituent, by the general formula (1−n)(K_1-xNa_x)Nb_yO₃-nM1M2O₃ in which M1 is any one of Ca, Sr, and Ba, and M2 is Zr, and x, y, and n respectively are within the ranges of: 0.25≦x≦1.00; 0.85≦y≦1.10; and 0.01≦n≦0.10. Alternatively, M2 is any one of Sn and Hf, and x, y, and n respectively are within the ranges of: 0.25≦x≦1.00; 0.90≦y≦1.05; and 0.01≦n≦0.10.

The present invention relates to forming the material represented by the following formula (1) into a layer having hexagonal crystalline structure, which is different from the orthorhombic crystalline structure of the material in bulk phase, so that the material can be used more effectively in various fields requiring multiferroic properties by obtaining multiferroic properties enhanced than the conventional multiferroic materials. RMnO₃, (R=Lanthanide) . . . (1)

Devices and methods for energy conversion based on the giant flexoelectric effect in non-calamitic liquid crystals. By preparing a substance comprising at least one type of non-calamitic liquid crystal molecules and stabilizing the substance to form a mechanically flexible material, flexible conductive electrodes may be applied to the material to create an electro-mechanical energy conversion device which relies on the giant flexoelectric effect to produce electrical and/or mechanical energy that is usable in such applications as, for example, power sources, energy dissipation, sensors/transducers, and actuators. The ability to directly and accurately measure the giant flexoelectric effect for different types of non-calamitic liquid crystal molecules is important for identifying molecules that may be effective for particular applications.

The present invention is directed to sensors that use wide band gap piezoelectric films such as aluminum nitride and zinc oxide. The films can be deposited with chemical and physical methods and etched or micro machined into miniature and micro sensing elements. Various piezoelectric sensing structures such as compression mode and cantilever-type accelerometers, diaphragm-type pressure sensors, and micro sensor arrays can be manufactured with the sensing elements. They can be used in the measurements of vibration, shock, dynamic pressure, stress, and high resolution ultrasound non-destructive test at high temperature up to 800-1000° C.

The invention relates to a Fe-Ga-based magnetostrictive wire and a method for preparing the same. The alloy composition (atom fraction) used in the method is Fe1-x-y-zGaxAlyMz, wherein M is selected from one or more than one of Co, B, Cr, V, Nb, Zr, Be, Y, Ti and the like; x is equal to between 0.10 and 0.30; y is equal to between 0.01 and 0.15; z is equal to between 0.000 and 0.1, and the balance is Fe. The invention makes use of a rotating water spinning method to prepare a Fe-Ga-based magnetostrictive microcrystalline or amorphous wire; and the method has the advantages of simple and convenient process, high wire-forming rate, good process repeatability and stability and the like. The wire prepared by the method has good roundness and linearity, and has higher magnetostrictive coefficient, good corrosion resistance and good mechanical property at the same time. The diameter of the prepared Fe-Ga-based magnetostrictive microcrystalline or amorphous wire is between 0.01 and 0.5 millimeter, and the amorphous wire can be made into an alloy wire with a nano-crystalline structure after heat treatment. Under a low magnetic field condition, the magnetostrictive property of the Fe-Ga-based magnetostrictive wire can reach 160 * 10<-6>.

The invention provides a novel class of room-temperature, single-phase, magnetoelectric multiferroic (PbFe_0.67W_0.33O₃)_x (PbZr_0.53Ti_0.47O₃)_1-x (0.2≦x≦0.8) (PFW_x−PZT_1-x) thin films that exhibit high dielectric constants, high polarization, weak saturation magnetization, broad dielectric temperature peak, high-frequency dispersion, low dielectric loss and low leakage current. These properties render them to be suitable candidates for room-temperature multiferroic devices. Methods of preparation are also provided.

A ferroelectric thin film element comprises a substrate and an epitaxial ferroelectric thin film provided on the substrate. The thin film satisfies z/z₀>1.003 and 0.997≦x/x₀≦1.003, where a crystal face of said thin film parallel to a crystal face of a surface of the substrate is taken as a Z crystal face, a face spacing of the Z crystal face is taken as z, a face spacing of the Z crystal face of a material constituting the thin film in a bulk state is taken as z₀, a crystal face of the thin film perpendicular to the Z crystal face is taken as an X crystal face, a face spacing of the X crystal face is taken as x and a face spacing of the X crystal face of the material constituting the thin film in a bulk state is taken as x₀.

A piezoelectric ceramic composition includes: a composite oxide, as a main component thereof, represented by the composition formula,

Pb_a[(Zn_1/3Nb_2/3)_xTi_yZr_z]O₃,

• • wherein a, x, y and z satisfy the following
  • relations, 0.96≦a≦1.03, 0.005≦x≦0.047,
  • 0.42≦y≦0.53, 0.45≦z≦0.56, and x+y+z=1, and the following additives in the indicated percentages by mass in relation to the main component,
  • Cu as a first additive, in a content α, in terms of Cu₂O, falling within a range 0<α≦0.5%;
  • at least one of Li, Co, Ni, Ga and Mg, as a second additive, in a content β, in terms of carbonate for Li, falling within a range 0<β≦0.1%, in a content δ1, in terms of oxide for Co, Ni and Ga, falling within a range 0<δ1≦0.2%, and in a content δ2, in terms of carbonate for Mg, falling within a range 0<δ2≦0.2%;
  • and at least one of Ta, Nb, W and Sb, as a third additive, in a content γ, in terms of oxide, falling within a range 0<γ≦0.6%.

It is an object of the present invention to provide a piezoelectric actuator which uses strontium ruthenate as the material of the bottom electrode, and which uses PMN-PT as the material of the piezoelectric layer. This piezoelectric actuator comprises a base layer (31, 20) of SiO₂ or Si ((100) orientation or (110) orientation), a buffer layer (41) constituted by strontium ruthenate (SRO), and a piezoelectric layer (44) constituted by a relaxor dielectric (PMN-PT) with a rhombohedral or quasi-cubic crystal structure oriented in the (001) direction at room temperature.

The invention discloses a Wheatstone-bridge-based pressure sensor and a manufacturing method thereof, which relate to the technical field of semiconductor pressure sensors. The pressure sensor comprises a bonding wafer, a bonding medium, a substrate, a buffer layer, a barrier layer, metal lead wires, a barrier layer, an empty cavity and ohmic electrodes, wherein the material of the buffer layer isgallium nitride, and the material of the barrier layers is In<x>Al<y>Ga<1 x y>N. The pressure sensor ensures the stability of resistance, is simple in manufacturing method, improves the manufacturingprecision of products, and can be used in a high-temperature environment.