Abstract: The present invention provides a MEMS speaker including a substrate sidewall enclosing a cavity. The substrate sidewall includes a first surface and a second surface, a sounding assembly that is arranged on the first surface of the substrate sidewall and also seals the cavity at the opening of the first surface, and a bracket disposed in the cavity. The sounding assembly includes a first sounding assembly and the second sounding assembly. Each sounding assembly includes a driving part and a flexible diaphragm. The flexible diaphragm closes the gap formed between the free ends of adjacent driving parts and between the free ends of the driving parts and the substrate sidewall. The present invention also provides a manufacturing method of MEMS speaker. The MEMS speakers provided by the present invention have high-quality acoustic performance.

Abstract: A positive electrode material, including a substrate and a first region located on a surface of the substrate, where a molar ratio of iodine element to nickel element in the first region is 0.25 to 1.5. In this application, iodine ion lattice doping is introduced into the surface layer of the positive electrode material, so that the structural stability of the positive electrode material under high temperatures and high voltages and the kinetic performance under large-rate charge/discharge conditions are effectively improved, thereby reducing gas production in high-temperature and high-voltage storage and temperature rise under large-rate charge/discharge conditions of the electrochemical device, and improving the comprehensive performance of the electrochemical device.

Abstract: A positive electrode material includes first monocrystalline particles, and the first monocrystalline particle has a first length-diameter ratio L1, where L1 satisfies 2?L1?5. The positive electrode material includes the first monocrystalline particle having the first length-diameter ratio L1, and a high length-diameter ratio of the first monocrystalline particle is conducive to reducing active crystal planes which cause side reactions on a surface of the positive electrode material, and suppressing structural phase change and interface side reactions of the positive electrode material, which leads to improved cycling performance and storage performance of the electrochemical apparatus at high voltage and high temperature.

Abstract: A positive electrode material, when an electrode including such positive electrode material is assembled with lithium metal to form a button cell and the button cell is charged and discharged at a current of 0.04 C in the voltage range of 2.8 V to 4.5 V, a differential capacity versus voltage dQ/dV curve obtained has a first oxidation peak and a first reduction peak in a range of 4.2 V to 4.5 V. The positive electrode material has high energy density as well as improved kinetic performance and high-temperature stability.

Abstract: A metal hydroxide includes Ni element. An axial lattice constant c ? of the metal hydroxide satisfies: 0.363x+4.2?c?0.363x+4.4, where, based on a total molar mass of a metal element in the metal hydroxide, a molar percentage of the Ni element in the metal hydroxide is x. The lattice constant c of the metal hydroxide falls within a specified value range. The positive electrode material prepared from the metal hydroxide serving as a precursor is of excellent structural stability in a charging and discharging environment, and improves the cycle performance, high-temperature performance, and safety performance of lithium-ion batteries.

Abstract: A positive electrode material, including a lithium transition metal oxide. As tested by X-ray diffractometry, a full width at half maximum FWHM(101) of a (101) crystal plane diffraction peak and a full width at half maximum FWHM(104) of a (104) crystal plane diffraction peak of the positive electrode material satisfy: FWHM(101)/FWHM(104)?0.7. This application further provides an electrochemical device and an electronic device that includes the positive electrode material. The positive electrode material is of excellent structural stability under high temperature and high voltage, and is of excellent kinetic performance under high-rate charging and discharging conditions.

Abstract: The invention discloses a piezoelectric speaker, including a substrate with a cavity therethrough a supporting structure covering the cavity a first drive structure stacked on the supporting structure, including alternately stacked first electrode layers and first piezoelectric layers a transmission structure stacked on the first drive structure, and a separation slot penetrating the supporting structure and the first drive structure to separate the first drive structure into a first piezoelectric driving part and a second piezoelectric driving part. A rigidity of the transmission structure is less than or equal to a rigidity of the first drive structure, and the rigidity of the first drive structure is less than or equal to a rigidity of the supporting structure. Compared with the prior art, the sound pressure level generated at the same moment is higher.

Abstract: One of the main objects of the present invention is to provide a speaker with optimized overall acoustic performance. To achieve the above-mentioned object, the present invention provides a speaker including: a base with an accommodation cavity; a vibration sounding assembly accommodated in the accommodation cavity, including a first diaphragm and a second diaphragm, and a driver fixed to the first diaphragm for driving the first diaphragm and the second diaphragm to vibrate and produce sound. The second diaphragm stacks on the first diaphragm, and a stiffness of the second diaphragm is different from a stiffness of the first diaphragm.

Abstract: A sound production device includes a substrate having a cavity and a plurality of cantilever diaphragms fixed on the substrate. Each of the plurality of the cantilever diaphragms includes a fixed end fixed on the substrate and a free end extending from the fixed end to a position suspended above the cavity. The free end includes a first surface and a second surface oppositely arranged. The free end and the substrate or other free ends are spaced to form a gap. The sound production device further includes a first dielectric elastomer actuator, a second dielectric elastomer actuator, and a flexible connector. The sound production device of the present disclosures adopts dielectric elastomer actuators on both of the upper and lower sides of the cantilever diaphragms to together act on the cantilever diaphragms, thereby improving the linearity of the sound production device.

Abstract: A MEMS speaker includes a substrate, a vibration sounding portion and a baffle plate with a through hole. The baffle plate, the substrate and the vibration sounding portion form a sounding inner cavity, and a volume of the sounding inner cavity can adjust a resonant frequency of the sounding inner cavity, so that the resonance frequency of the sounding inner cavity resonate with a preset frequency of the MEMS speaker. A speaker assembly structure further provided includes a speaker, a fixing portion, and a baffle plate, the speaker and the baffle plate together enclose and form a sounding inner cavity, the fixing portion and the speaker are fixedly connected together and form a sealing structure. A sound pressure level of the MEMS speaker and the speaker assembly structure is high and harmonic distortion of the MEMS speaker and the speaker assembly structure is small.

Abstract: The invention discloses a piezoelectric speaker, including a substrate with a cavity therethrough a supporting structure covering the cavity a first drive structure stacked on the supporting structure, including alternately stacked first electrode layers and first piezoelectric layers a transmission structure stacked on the first drive structure, and a separation slot penetrating the supporting structure and the first drive structure to separate the first drive structure into a first piezoelectric driving part and a second piezoelectric driving part. A rigidity of the transmission structure is less than or equal to a rigidity of the first drive structure, and the rigidity of the first drive structure is less than or equal to a rigidity of the supporting structure. Compared with the prior art, the sound pressure level generated at the same moment is higher.

Abstract: A resonator includes a silicon substrate, a bottom electrode stacked on a portion of the silicon substrate, a piezoelectric layer covering the bottom electrode and another portion of the silicon substrate, a top electrode stacked on the piezoelectric layer, and a Bragg reflecting ring. The Bragg reflecting ring is formed on a side of the piezoelectric layer connected to the top electrode and surrounds the top electrode. The Bragg reflecting ring includes a Bragg high-resistivity layer and a Bragg low-resistivity layer alternately arranged along the radial direction of the Bragg reflecting ring. An acoustic impedance of the Bragg high-resistivity layer is greater than an acoustic impedance of the Bragg low-resistivity layer. The Bragg reflecting ring forms reflection surfaces to reflect the laterally propagating clutter waves, thereby suppressing the parasitic mode in the working frequency band, improving the frequency response curve of the resonator and the overall performance of the resonator.

Abstract: A sound production device includes a substrate having a cavity and a plurality of cantilever diaphragms fixed on the substrate. Each of the plurality of the cantilever diaphragms includes a fixed end fixed on the substrate and a free end extending from the fixed end to a position suspended above the cavity. The free end includes a first surface and a second surface oppositely arranged. The free end and the substrate or other free ends are spaced to form a gap. The sound production device further includes a first dielectric elastomer actuator, a second dielectric elastomer actuator, and a flexible connector. The sound production device of the present disclosures adopts dielectric elastomer actuators on both of the upper and lower sides of the cantilever diaphragms to together act on the cantilever diaphragms, thereby improving the linearity of the sound production device.

Abstract: A MEMS speaker includes a substrate, a vibration sounding portion and a baffle plate with a through hole. The baffle plate, the substrate and the vibration sounding portion form a sounding inner cavity, and a volume of the sounding inner cavity can adjust a resonant frequency of the sounding inner cavity, so that the resonance frequency of the sounding inner cavity resonate with a preset frequency of the MEMS speaker. A speaker assembly structure further provided includes a speaker, a fixing portion, and a baffle plate, the speaker and the baffle plate together enclose and form a sounding inner cavity, the fixing portion and the speaker are fixedly connected together and form a sealing structure. A sound pressure level of the MEMS speaker and the speaker assembly structure is high and harmonic distortion of the MEMS speaker and the speaker assembly structure is small.

Abstract: One of the main objects of the present invention is to provide a speaker with optimized overall acoustic performance. To achieve the above-mentioned object, the present invention provides a speaker including: a base with an accommodation cavity; a vibration sounding assembly accommodated in the accommodation cavity, including a first diaphragm and a second diaphragm, and a driver fixed to the first diaphragm for driving the first diaphragm and the second diaphragm to vibrate and produce sound. The second diaphragm stacks on the first diaphragm, and a stiffness of the second diaphragm is different from a stiffness of the first diaphragm.

Abstract: The present invention provides a MEMS speaker including a substrate sidewall enclosing a cavity. The substrate sidewall includes a first surface and a second surface, a sounding assembly that is arranged on the first surface of the substrate sidewall and also seals the cavity at the opening of the first surface, and a bracket disposed in the cavity. The sounding assembly includes a first sounding assembly and the second sounding assembly. Each sounding assembly includes a driving part and a flexible diaphragm. The flexible diaphragm closes the gap formed between the free ends of adjacent driving parts and between the free ends of the driving parts and the substrate sidewall. The present invention also provides a manufacturing method of MEMS speaker. The MEMS speakers provided by the present invention have high-quality acoustic performance.

Abstract: One of the main objects of the present invention is to provide a MEMS acoustic sensor with improved acoustic performance and liability. To achieve the above-mentioned objects, the present invention provides a MEMS acoustic sensor, including: a base with a cavity; a number of structural layers fixed on the base, each including a fixed end fixed to the base and a suspension end extending from the fixed end for being suspended above the cavity, the suspension end being spaced from the base for forming a slit; a piezoelectric functional layer on the suspension end; and a flexible connector completely covering the slit; wherein a Young's modulus of the flexible connector is smaller than a Young's modulus of the structural layer.

Abstract: One of the main objects of the present invention is to provide a MEMS speaker with improved high frequency acoustic performance. To achieve the above-mentioned object, the present invention provides a MEMS speaker including a base with a first cavity and two openings opposite to each other; a substrate covering one of the openings; a diaphragm fixed to the base and covers the other opening; and a MEMS driver. The MEMS driver includes a first support part forming a distance from the diaphragm, a second support part extending from an edge of the first support part toward the diaphragm for supporting the diaphragm, and a piezoelectric member attached to the first support part.

Abstract: A cathode material includes a lithium composite oxide having lithium (Li) and at least one selected from cobalt (Co), nickel (Ni), manganese (Mn) or aluminum (Al); and a lithium-containing transition metal nitride. A transition metal in the lithium-containing transition metal nitride is at least one selected from cobalt (Co), nickel (Ni), or manganese (Mn). The cathode material provides excellent dynamic performance.

Abstract: A resonator includes a silicon substrate, a bottom electrode stacked on a portion of the silicon substrate, a piezoelectric layer covering the bottom electrode and another portion of the silicon substrate, a top electrode stacked on the piezoelectric layer, and a Bragg reflecting ring. The Bragg reflecting ring is formed on a side of the piezoelectric layer connected to the top electrode and surrounds the top electrode. The Bragg reflecting ring includes a Bragg high-resistivity layer and a Bragg low-resistivity layer alternately arranged along the radial direction of the Bragg reflecting ring. An acoustic impedance of the Bragg high-resistivity layer is greater than an acoustic impedance of the Bragg low-resistivity layer. The Bragg reflecting ring forms reflection surfaces to reflect the laterally propagating clutter waves, thereby suppressing the parasitic mode in the working frequency band, improving the frequency response curve of the resonator and the overall performance of the resonator.