57 results about "Piezoelectric constant" patented technology

The invention discloses a method for preparing lead-free piezoelectric ceramic with high density and low defect density by hot pressed sintering, which comprises the following steps: embedding a green body formed by pressing raw materials in an embedding body formed by stacking porous metal oxide particles for hot pressed sintering, and exchanging controlled gas in the hot pressed sintering process; in the hot pressing process, a green body is embedded in a porous metal oxide particle accumulation body, the accumulation body can form a communicated gas channel on the microscopic scale and provide physical protection and volatilization blocking for the green body, and generation of oxygen vacancies can be effectively inhibited, volatilization of alkali metal is reduced, and generation of impure phases is inhibited in the hot pressing high-temperature pressed stage; therefore, the defect density is reduced while the high density is realized, the piezoelectric constant, the polarization capability and the high-temperature stability are synergistically improved, the dielectric loss is reduced, and the durability is improved.

To provide a piezoelectric film having high piezoelectricity and high transparency. [Solution] A piezoelectric film mainly composed of a fluororesin, wherein the piezoelectric constant d 31 A piezoelectric film having a density of 29 pC / N or more and 50 pC / N or less, an internal haze of 0.01% or more and 1.5% or less, and a retardation of 100 nm or more and 3000 nm or less.

To provide a fluororesin piezoelectric film which is obtained from a fluororesin having low melt viscosity and has high breaking strength.SOLUTION: Wherein the fluororesin piezoelectric film has a retardation of 50nm or more and 3000nm or less, an internal haze of less than 1.2%, a breaking strength of 310MPa or more and 550MPa or less, and a piezoelectric coefficient d33 of 5. 0pC / N or more and 40. 0pC / N or less.SELECTED DRAWING: None

The invention discloses a texture preparation method for high-performance lead-free piezoelectric ceramics of bismuth ferrite-barium titanate. The general formula of the ceramic composition is as follows, where the molar fraction ratio of BiFeO3 and BaTiO3 is 2:1, x, y, t, and m all represent molar fractions, and 0 < x ≤ 0.05, 0 < y ≤ 0.05, 0 < t ≤ 0.05, 0 < m ≤ 0.05. In the sintering stage of the invention, a temperature gradient field is constructed to make the ceramic grains grow texture-directionally, and a textured piezoelectric ceramic with a piezoelectric constant d 33 reaching above 1000 pC / N at 350 °C and a T dr reaching above 350 °C is obtained. The preparation process of the invention is simple, and the prepared ceramic has excellent high-temperature performance and can be applied to the field of high-temperature piezoelectricity.

The invention discloses a piezoelectric film with bionic textures and a preparation method and application thereof, the piezoelectric film is formed by directionally stacking and depositing fibers with core-shell structures, the piezoelectric film has a gully-bulge alternating bionic morphology imitating human skin surface textures, and the aperture of the piezoelectric film is gradually increased from an attachment surface in the thickness direction; the fiber having the core-shell structure comprises: a core layer having a porous structure and containing modified molybdenum disulfide and polyester; the shell layer wraps the core layer, and the shell layer contains collagen; the piezoelectric film comprises a sensing unit area and a flexible connection area, the collagen crosslinking degree of the sensing unit area is larger than 75%, and the collagen crosslinking degree of the flexible connection area is 40%-55%. Under the synergistic effect of materials and structures, the piezoelectric film not only has a high piezoelectric constant, but also shows excellent mechanical properties, air permeability and moisture penetrability, and has wide application prospects in the fields of electronic skin, health monitoring and the like.

This invention discloses a piezoelectric ceramic membrane and its preparation method, comprising a modified lead zirconate titanate-based ceramic and a surface functional coating. The modified lead zirconate titanate-based ceramic serves as the substrate, wherein x = 0.52-0.54, and contains A-site doping elements, B-site doping elements, and sintering aids. The surface functional coating is silicon nitride, with a thickness of 100-300 nm, and is prepared by low-pressure chemical vapor deposition (LPCVD). This invention, through La, Nb, Sr, and Mn multi-component composite doping, significantly reduces the temperature coefficients of the piezoelectric constant d31 and the electromechanical coupling coefficient k31, achieving a displacement drift ≤ ±3% over a wide temperature range of -20℃ to 85℃, ensuring stable micro-infusion accuracy under different environments. The integrated composite membrane structure with a central island and annular support improves displacement linearity while ensuring a large stroke, reducing hysteresis and creep, and meeting the ultra-high precision infusion requirements of 0.05U~0.01U.

The invention provides a lead-free piezoelectric ceramic material, a preparation method thereof and a piezoelectric device. The lead-free piezoelectric ceramic material is represented by a chemical general formula as follows: (1-x-y) (K1-aNaa) (Nb1-bMb) O < 3-x > AWO < 4-y > BMoO < 4 >, wherein (K1-aNaa) (Nb1-bMb) O3 represents a potassium-sodium niobate-based ceramic material, a is greater than or equal to 0.4 and less than or equal to 0.6, b is greater than or equal to 0 and less than or equal to 0.1, and M is a doped metal element; x and y are mole fractions and satisfy 0 lt; x is less than or equal to 0.05, 0lt; y is less than or equal to 0.05, and 0 lt; x + y < = 0.1; the AWO4 is tungstate, and the BMoO4 is molybdate. Through the synergistic effect of tungstate and molybdate, the sintering temperature of the lead-free piezoelectric ceramic material is reduced, the piezoelectric constant of the lead-free piezoelectric ceramic material is improved, the dielectric loss of the lead-free piezoelectric ceramic material is reduced, the comprehensive performance of the lead-free piezoelectric ceramic material is greatly improved, and the lead-free piezoelectric ceramic material can be applied to piezoelectric devices such as piezoelectric motors with high requirements for piezoelectric performance.

The invention provides a lead-free piezoelectric ceramic material and a preparation method and application thereof. The piezoelectric constant d33 of the ceramic material is larger than or equal to 320 pC / N, the mechanical quality factor Qm is larger than or equal to 1090, and the dielectric loss tan delta is smaller than or equal to 1.8%. Due to the special performance parameters of the lead-free piezoelectric ceramic material, on the premise of keeping environment friendliness, the energy conversion efficiency can be effectively improved, the heat yield is reduced, and the lead-free piezoelectric ceramic material has better stability.

The invention provides a piezoelectric material and a preparation method thereof, a piezoelectric device and electronic equipment, the chemical general formula of the piezoelectric material is xPb (Mn1 / 2W1 / 2) O3-(1-x) [0.15 Pb (Zn1 / 3Nb2 / 3) O3-0.85 Pb (Zr0. 5Ti0. 5) O3], and x is greater than or equal to 0.05 and less than or equal to 0.08. A solid-phase synthesis method is adopted, the mechanical quality factor, the electromechanical coupling coefficient, the piezoelectric constant, the dielectric loss, the Young modulus and the like of the prepared piezoelectric material are improved by doping lead tungstate manganate, regulating and controlling the parameter range of x and controlling the sintering temperature in the synthesis process and preferably adding rare earth elements Yb, Er, Eu and the like, the preparation process is simple, the raw materials are environmentally friendly, and the method is suitable for industrial production. When the piezoelectric material is applied to high-frequency piezoelectric devices and electronic equipment, the use requirements of high performance and low power consumption can be met.

The application relates to the technical field of piezoelectric constant measurement of piezoelectric materials, and discloses a piezoelectric constant measurement device for piezoelectric materials, which comprises a machine body, a measurement mechanism, a static force applying mechanism and a dynamic force applying mechanism. The measurement mechanism comprises a first conductive part, a second conductive part and a measurement assembly. The first conductive part is arranged in a spaced mode with the second conductive part. The measurement assembly is electrically connected with the first conductive part and the second conductive part, and is used for measuring the charge amount released by the piezoelectric material when the piezoelectric material is pressed. The static force applying mechanism is connected with the first conductive part and the machine body, and is used for applying a static force to the piezoelectric material through the first conductive part. The dynamic force applying mechanism comprises a dynamic force sensor and a vibration exciter. The vibration exciter is connected with the machine body and the dynamic force sensor, and is connected with the second conductive part through the dynamic force sensor, and is used for applying a dynamic force to the piezoelectric material. The piezoelectric constant of the piezoelectric material can be accurately measured, and the interference of the error of the reference material on the piezoelectric constant measurement of the piezoelectric material is avoided.

The invention provides a secondary battery, a preparation method thereof and electric equipment. The secondary battery comprises one or more battery cells, the battery cell comprises a negative pole piece; the negative pole piece comprises a microcapsule; the microcapsule comprises an inner core and a shell layer arranged on the surface of the inner core; the inner core comprises a polymer, a lithium salt and chain carbonate; the shell layer comprises at least one of an organic piezoelectric material, a thermosensitive high polymer material and an acid response type high polymer material; the secondary battery satisfies at least one of the following conditions: 1) the piezoelectric constant d33 of the organic piezoelectric material is 10-50 pC / N; 2) the glass transition temperature of the thermosensitive polymer material is 50-100 DEG C, and 3) the acid response type polymer material comprises an acidolysis material which is degraded when the acid concentration is 3-120 ppm. The secondary battery provided by the invention has the advantages of less electrolyte consumption, good cycle performance and small internal resistance.

The application discloses a high-impedance near-zero temperature drift high-temperature piezoelectric crystal material and a growth method and application thereof, and belongs to the technical field of piezoelectric crystal growth. x Gd 1‑x Ca4O(BO3)3, x=0.1-0.3, and the high-impedance near-zero temperature drift high-temperature piezoelectric crystal material can be obtained by using a conventional Czochralski method to grow a large-size high-quality single crystal, and the growth process is simple and easy to process. The piezoelectric special-shaped element made of the crystal material has an effective longitudinal piezoelectric constant d 33 The effective shear piezoelectric constant d 26 The high-temperature 1000 DEG C resistivity can reach 10 6 Ω.cm; the piezoelectric constant change rate in the range from room temperature to 1000 DEG C is below 5%, and the crystal material has the near-zero temperature drift characteristic and high-temperature resistance.

To provide a fluorine-based resin piezoelectric film having a low shrinkage factor during heating and high transparency.SOLUTION: A fluororesin piezoelectric film having a maximum shrinkage of 2.5% or less when held at 80 °C for 30 minutes, a retardation of 50nm or more and 3000nm or less, an internal haze of less than 1.2%, and a piezoelectric coefficient d33 of 5. 0pC / N or more and 40. 0pC / N or less.SELECTED DRAWING: None

The invention discloses a high-performance PSSN-PMN-PZ-PT-Cu textured piezoelectric ceramic material and a preparation method thereof, the chemical composition expression is Pb1-1.5 aSma [(Sc1 / 2Nb1 / 2) x (Mg1 / 3Nb2 / 3) yZrzTi (1-x-y-z)] O3-bCuO-cBaTiO3, a, x, y and z all represent molar fractions, b and c respectively represent the mass percentages of CuO and BaTiO3, a is greater than or equal to 0.005 and less than or equal to 0.025, and c is greater than or equal to 0.15 lt; x < = 0.5, 0.05 < = y < = 0.15, 0.03 < = z < = 0.15, 0.1 < = b < = 1, and 0.5 < = c < = 10; the material is subjected to multiple times of ball milling, presintering and powdering, then is subjected to tape casting, lamination, isostatic pressing and sintering in an oxygen atmosphere to obtain [001] oriented ceramic, and finally, is coated with an electrode and is polarized to prepare the [001] oriented ceramic. After the material is sintered at 900 DEG C, the piezoelectric constant reaches 820 pC / N, and the Curie temperature reaches 238 DEG C.

Provided is a piezoelectric film having excellent piezoelectric properties and high transparency. The piezoelectric film according to the present invention contains a fluorine-based resin as a main component, has a piezoelectric constant d31 of 15-50 pC / N, an electromechanical coupling constant k31 of at least 0.14, an internal haze of 0.01-10.0%, and a retardation of 100-3000 nm.

The invention discloses a high-titanium-doped lithium niobate target material, a preparation method thereof and a sensor, and the preparation method comprises the following steps: adding an acidic lithium-containing solution into a mixed solution of titanium and niobium, and reacting to obtain gel; performing heat treatment on the gel to obtain powder; and preparing the high-titanium doped lithium niobate target material according to the powder. The invention provides a wet chemical method for preparing the Ti-doped LiNbO3 target material, a high-density and fine-grain target material microstructure is easy to obtain, elements are uniformly distributed, and a relatively high Ti element proportion can be doped. Besides, the Ti-doped LiNbO3 piezoelectric coating obtained on the basis of the high-titanium-doped lithium niobate target material is extremely high in substance purity and has very excellent piezoelectric performance, and the piezoelectric constant d33 is greatly increased and reaches 12.4 pC / N.

The present application provides a piezoelectric material and a preparation method therefor, a piezoelectric device, and an electronic device. The general chemical formula of the piezoelectric material comprises: xPb(Mn1 / 2W1 / 2)O3-(1-x)[0.15Pb(Zn1 / 3Nb2 / 3)O3-0.85Pb(Zr0.5Ti0.5)O3], wherein 0.05 ≤ x ≤ 0.08. In the present application, a solid-phase synthesis method is used to improve the mechanical quality factor, electromechanical coupling coefficient, piezoelectric constant, dielectric loss, Young's modulus, etc. of the prepared piezoelectric material by doping same with lead tungstate, adjusting the range of parameter x and controlling the sintering temperature during synthesis, and preferably adding rare earth elements Yb, Er, Eu, etc.; and the preparation process is simple, and the raw materials are environmentally friendly. The piezoelectric material, when used in high-frequency piezoelectric devices and electronic devices, can meet the use requirements of high performance and low power consumption.

The application relates to the technical field of functional ceramic materials, in particular to a lead metaniobate-based piezoelectric ceramic, a preparation method and application thereof. The high-dielectric high-curie-temperature lead metaniobate-based piezoelectric ceramic has a chemical formula of Pb 0.87‑x Ba 0.12 Ca 0.01 La x Nb 1.9 W 0.1 O6+0.1wt%CeO2+0.05wt%Cr2O3, wherein 0<=x<=0.015. The obtained lead metaniobate-based piezoelectric ceramic has the characteristics of excellent electrical performance and high curie temperature, and has a d 33 =105pC / N, k t =0.41, epsilon r =510, T c =536 DEG C, tan delta=0.45%, and has high dielectric performance and piezoelectric constant under the premise of high curie temperature, and the comprehensive performance is superior to that of the existing lead metaniobate-based piezoelectric ceramic.

This invention relates to the field of piezoelectric ceramics technology, and more specifically, to a high-performance composite piezoelectric ceramic and its preparation method. A method for preparing a high-performance composite piezoelectric ceramic includes the following steps: mixing and ball-milling a matrix ceramic powder with a β-Si3N4 whisker dispersion; subsequently drying, adding a binder, granulating, and pressing to obtain a green body; heating and debinding the green body and sintering to obtain a piezoelectric ceramic sample; and polishing, silvering, and polarizing the piezoelectric ceramic sample to obtain the high-performance composite piezoelectric ceramic. Introducing β-Si3N4 whiskers into the high-performance composite piezoelectric ceramic is beneficial to improving its mechanical quality factor. In the matrix ceramic powder, through the composite doping of MgO and Sm2O3, MgO and Sm2O3 can produce a synergistic reinforcement effect, increasing the piezoelectric constant of the high-performance composite piezoelectric ceramic.

This invention provides a scandium-added gallium nitride material, a piezoelectric material thereof, a MEMS device using the piezoelectric material, the scandium-added gallium nitride material and a ferroelectric material thereof, and an electronic component using the ferroelectric material. Furthermore, it provides a method for manufacturing the scandium-added gallium nitride material, which has a piezoelectric constant d exceeding 14 pC / N. 33 It has a piezoelectric constant d exceeding 16.9 pC / N. 33 In particular, it has a higher maximum piezoelectric constant d than aluminum nitride with added scandium. 33 The piezoelectric constant d with a value of 27.6 pC / N 33 A nitride material, composed of the chemical formula Sc x Ga 1‑x N represents the range where x is above 0.39 and below 0.54, and the length of the c-axis in the crystal structure is 4.94 × 10⁻⁶. ‑10 m or more and less than 5.2 × 10 ‑10 The range of m.

The invention relates to the technical field of semiconductor processes, in particular to an ultrasonic sensor based on a TFT (thin film transistor) and a preparation process thereof.The ultrasonic sensor structurally comprises a substrate, a functional layer and the TFT, and the substrate is provided with a front face and a back face which are opposite; the functional layer is arranged on the front face of the substrate, the TFT is arranged on the front face of the functional layer, and the process comprises the steps of growing the functional layer on the front face of the substrate and growing the TFT on the front face of the functional layer. The functional layer is arranged in the functional layer between the TFT and the substrate, so that the propagation path of sound waves in the sensor is optimized, the energy loss is reduced, and the sound wave energy conversion efficiency of the piezoelectric layer is remarkably improved. Meanwhile, the PZT material is used for replacing the PVDF material to grow on the substrate to serve as the piezoelectric material, and the characteristics of high piezoelectric constant and high dielectric constant of the PZT material are utilized, so that the whole sensor has the characteristics of high resolution, high signal-to-noise ratio, high sensitivity and high penetrability.

The invention relates to the technical field of piezoelectric ceramic material preparation, and discloses a bismuth ferrite-barium titanate textured piezoelectric ceramic material with low sintering temperature and high piezoelectric property and a preparation method thereof, and the preparation method comprises the following steps: preparing a bismuth ferrite precursor template with copper oxide loaded on the surface; dispersing the template, barium titanate, bismuth oxide powder and a hyperbranched polyesteramide dispersing agent into photosensitive resin to prepare slurry; performing slip casting and in-situ photocuring under a static strong magnetic field; and carrying out glue discharging and reactive sintering to obtain a target product. An interface liquid phase is formed at the initial stage of sintering by using copper oxide on the surface of the template, and template particles are anchored through capillary force, so that template deflection in the densification process is inhibited, and the ceramic texture degree is improved; meanwhile, bismuth volatilization is inhibited through liquid-phase-assisted low-temperature sintering, the leakage current of the material is reduced, and the prepared ceramic has a high piezoelectric constant, a high Curie temperature and good insulativity.

The application relates to the technical field of semiconductor processes, in particular to an ultrasonic sensor based on a TFT transistor and a preparation process thereof, and the structure comprises a substrate, a functional layer and a TFT transistor, the substrate has opposite front and back surfaces; the functional layer is arranged on the front surface of the substrate, and the TFT transistor is arranged on the front surface of the functional layer; the process comprises: growing the functional layer on the front surface of the substrate and growing the TFT transistor on the front surface of the functional layer. The functional layer is arranged in the functional layer between the TFT transistor and the substrate, the propagation path of the sound wave in the sensor is optimized, the energy loss is reduced, and the sound wave energy conversion efficiency of the piezoelectric layer is significantly improved. Meanwhile, the PZT material is used to replace the PVDF material to grow on the substrate as the piezoelectric material, the PZT material has the characteristics of high piezoelectric constant and high dielectric constant, and the whole sensor has the characteristics of high resolution, high signal-to-noise ratio, high sensitivity and high penetration.

The application discloses a preparation process of a lead zirconate titanate (PZT) film layer, a film layer structure and application thereof, and relates to the technical field of piezoelectric material film layer preparation. The preparation process comprises the following steps: S1, forming a low tensile stress silicon nitride layer on the surface of a substrate, which is used for homogenizing the in-plane stress gradient of a wafer; and S2, forming a piezoelectric functional layer on the surface of the silicon nitride layer in a sputtering mode, wherein the piezoelectric thin film material of the piezoelectric functional layer is lead zirconate titanate (PZT). The film layer structure and the preparation process thereof adopt the silicon nitride layer to relieve the thermal mismatch stress of the piezoelectric functional layer system, can improve the piezoelectric constant e31 of the central region of the wafer, and improve the uniformity of the whole wafer.

Provided is a piezoelectric single crystal comprising an internal bias electric field, a method of manufacturing the same, and piezoelectric and dielectric application components using the piezoelectric single crystal. The piezoelectric single crystal shows that as a change in each composition of [A] site ions, [B] site ions and [O] site ions from a perovskite type crystal structure ([A][B]O3), and oxygen partial-pressure during heat treatment in terms of a manufacturing process are controlled, while maintaining the inherent high dielectric constant and piezoelectric constant, the high internal bias electric field (EI) characteristic essential for the electrical stability of the piezoelectric single crystal is simultaneously satisfied. Therefore, piezoelectric application components and dielectric application components using the piezoelectric single crystal having excellent characteristics can be used in a wide temperature range and operating voltage conditions.

The invention discloses textured piezoelectric ceramic as well as a preparation method and application thereof, and belongs to the technical field of piezoelectric ceramic materials. According to the method, a PMS-PZT ternary solid solution with relatively high Qm and electromechanical coupling coefficient k is selected, a foundation is laid for comprehensive performance, a BZT seed crystal template is introduced, and a high texture degree lt is prepared by utilizing a template grain growth method; 001gt, 001gt; according to the oriented PMS-PZT textured piezoelectric ceramic, the high piezoelectric constant and the high mechanical quality factor are synergistically improved, the textured structure also reduces the dielectric loss, and the characteristic of high Curie temperature is reserved. According to the preparation technology, large-scale preparation of the texture piezoelectric ceramic green bodies is achieved through the steps of tape casting, lamination and the like, the process is clear, controllability is high, a feasible path is provided for industrial production, the problem that the piezoelectric ceramics are hard and soft is solved, and the assistance to design and application of high-power piezoelectric ceramics is remarkable.

A multilayer piezoelectret film element, a polymeric porous sheet, and a method for preparing them are disclosed. The present disclosure ensures that the gas can be ionized without damaging the polymeric porous sheet by adjusting the gap between pores and the dielectric strength of the polymeric porous sheet in the multilayer piezoelectret film element. The polymeric porous sheet has a high piezoelectric constant after electric polarization and surface metallization treatment, and can generate a significant amount of charge under mechanical pressure, thereby exhibiting high sensitivity in applications such as piezoelectric sensors, and solving the problems of low piezoelectric activity and fast loss of piezoelectric activity of the polarized polymeric piezoelectret film element in the art. Moreover, the production process is simple, which can ensure continuous production of the polymeric piezoelectret film element.

The invention relates to an electric leakage risk testing device for a new energy automobile battery assembly, and relates to the technical field of battery electric leakage testing, the electric leakage risk testing device comprises a supporting rack, a conveying rack is arranged in the supporting rack, a bearing plate is arranged in the supporting rack, a loading plate is mounted on the bearing rack, and a first cam disc is rotatably mounted on the inner side of the loading plate; a first transmission plate is arranged on the periphery of the first cam plate, a first fluted disc is arranged on one side of the first transmission plate, a second cam plate and a third cam plate are installed in the lifting frame and used for adjusting the vertical arrangement height of the first long rod and the vertical arrangement height of the second long rod respectively, and a first voltage measuring pen and a second voltage measuring pen are arranged at the bottom of the first long rod and the bottom of the second long rod respectively. According to the invention, the working condition of the battery unit under instantaneous current impact can be truly reproduced, and the piezoelectric constant measurement error caused by constant current and pyroelectric effect in a static test is effectively avoided, so that the accuracy of electric leakage risk assessment is greatly improved.

The application provides a lead-free piezoelectric ceramic material, a preparation method thereof and a piezoelectric device. The lead-free piezoelectric ceramic material is expressed by a chemical general formula as follows: (1-x-y)(K 1‑a Na a )(Nb 1‑b M b )O3-xAWO4-yBMoO4; wherein (K 1‑a Na a )(Nb 1‑b M b )O3 represents a potassium sodium niobate-based ceramic material, 0.4<=a<=0.6, 0<=b<=0.1, M is a doped metal element; x and y are molar fractions, and satisfy: 0

The application provides an ultrasonic transducer, a preparation method thereof and an electronic device. The preparation method of the ultrasonic transducer comprises the following steps: coating a piezoelectric polymer solution on a first electrode, drying under the condition that the relative humidity is less than 30%, and forming a piezoelectric film; sequentially performing crystallization and polarization on the piezoelectric film, and forming a piezoelectric layer; and forming a second electrode on the piezoelectric layer, so as to obtain the ultrasonic transducer. Through the preparation process, the transparency and piezoelectric constant of the formed piezoelectric layer can be improved, and the performance of the ultrasonic transducer is optimized.