Abstract: The present disclosure discloses a bipolar transistor type MEMS pressure sensor and a preparation method thereof. The bipolar transistor type MEMS pressure sensor includes a thin film, a cantilever beam and a bipolar transistor. The bipolar transistor includes a base region, a collector region and an emitter region. The base region is configured to sense deformation of the thin film through a change in resistance value. For the bipolar transistor type MEMS pressure sensor of the disclosure, sensitivity of the sensor can be effectively improved without changing the performance indicators such as the measurement range and nonlinearity. Meanwhile, the bipolar transistor is used as a pressure-sensitive element, so that temperature drift of the sensor can be effectively inhibited.

Abstract: The present application discloses a packaging structure and method of an MEMS pressure sensor. The packaging structure of the MEMS pressure sensor includes: a film, forming a sealing chamber with a base, during manufacturing the sealing chamber is internally equipped with a sensing medium and a pressure sensor chip, when the external pressure increases, the film bends towards an inner side of the sealing chamber to cause the sealing chamber to contract and transmit pressure to the pressure sensor chip through the sensing medium. The packaging structure of the present application can avoid the sensing chip from being damaged by excessive contraction of the sealing chamber due to pressure overload, and thus achieves overload protection.

Abstract: The present application discloses a packaging structure and method of an MEMS pressure sensor. The packaging structure of the MEMS pressure sensor includes: a film, forming a sealing chamber with a base, during manufacturing the sealing chamber is internally equipped with a sensing medium and a pressure sensor chip, when the external pressure increases, the film bends towards an inner side of the sealing chamber to cause the sealing chamber to contract and transmit pressure to the pressure sensor chip through the sensing medium. The packaging structure of the present application can avoid the sensing chip from being damaged by excessive contraction of the sealing chamber due to pressure overload, and thus achieves overload protection.

Abstract: A multimode optical fiber includes a core and a cladding covering the core. The core has a radius in a range of 23.75-26.25 ?m. A refractive index profile of the core has a graded refractive index distribution with a refractive index distribution index ? in a range of 1.80-1.89. The core has a maximum relative refractive index difference ?1% in a range from 1.0% to 1.15%. The multimode optical fiber has a fusion loss less than or equal to 0.08 dB. The multimode optical fiber is applied in a middle-and-long distance distributed temperature-measuring system, and a temperature-measuring distance of the system reaches 10 km to 27 km. The system includes a pulsed laser light source, a wavelength division multiplexer, an avalanche photodiode, a data acquisition device, an upper computer, and the temperature-measuring multimode optical fiber.

Abstract: A multimode optical fiber includes a core and a cladding covering the core. The core has a radius in a range of 23.75-26.25 ?m. A refractive index profile of the core has a graded refractive index distribution with a refractive index distribution index ? in a range of 1.80-1.89. The core has a maximum relative refractive index difference ?1% in a range from 1.0% to 1.15%. The multimode optical fiber has a fusion loss less than or equal to 0.08 dB. The multimode optical fiber is applied in a middle-and-long distance distributed temperature-measuring system, and a temperature-measuring distance of the system reaches 10 km to 27 km. The system includes a pulsed laser light source, a wavelength division multiplexer, an avalanche photodiode, a data acquisition device, an upper computer, and the temperature-measuring multimode optical fiber.

Abstract: The present invention discloses a device for detecting axis coplanarity of orthogonal rotary shafts having a built-in intersection, wherein a front assembly rotary body is coaxially connected on a front assembly housing, the front assembly rotary body and a rear assembly housing are fixedly connected with each other, the rear assembly rotary body is mounted in the rear assembly housing, a first three dimension movement fine tuning mechanism is mounted at an end of the rear assembly rotary body, the first three dimension movement fine tuning mechanism is connected with a standard sphere through a connecting rod, the three dimension movement fine tuning mechanisms are provided in the horizontal direction of the standard sphere and below the standard sphere in vertical direction, and two non-contact displacement sensors are mounted on said two three dimension movement fine tuning mechanisms respectively.

Abstract: A guide rail precision rotation apparatus is provided with a housing of torque motor and a bearing housing fixedly arranged on an upper surface of a base, and a bearing sleeved on an inner edge step at the upper end of bearing housing. The inner ring of bearing is sleevingly connected to an intermediate rotating body, the lower end of the body is connected to a bearing inner ring cap; a round grating is provided at an outer edge of lower end of the cap, a connecting piece is arranged on the motor, the lower end of connecting piece is fixedly connected to a rotary shaft of the motor, the connecting piece and the body are both connected to the lower end of a fine movement mechanism, and the upper end face of fine movement mechanism is fixedly connected to a rotary worktable.

Abstract: A macro-micro actuated distended guide rail precision rotation apparatus, having a housing of a torque motor and a bearing housing, both fixedly arranged on an upper surface of a base, and a bearing sleeved on the bearing housing. The inner ring of the bearing sleevingly connected to an intermediate rotating body connected to a bearing inner ring cap. A grating is provided at a lower end of the bearing inner ring cap. A connecting piece is arranged on the upper surface of the housing of the torque motor. The lower end of the connecting piece is fixedly connected to a rotary shaft of the torque motor. The connecting piece and the intermediate rotating body are both connected to the lower end of a fine movement mechanism fixedly connected to a rotary worktable. The rotation apparatus allows for highly precise macro-and-micro linked control, and for rotation control of great rotation range.

Abstract: The present invention discloses a device for detecting axis coplanarity of orthogonal rotary shafts having a built-in intersection, wherein a front assembly rotary body is coaxially connected on a front assembly housing, the front assembly rotary body and a rear assembly housing are fixedly connected with each other, the rear assembly rotary body is mounted in the rear assembly housing, a first three dimension movement fine tuning mechanism is mounted at an end of the rear assembly rotary body, the first three dimension movement fine tuning mechanism is connected with a standard sphere through a connecting rod, the three dimension movement fine tuning mechanisms are provided in the horizontal direction of the standard sphere and below the standard sphere in vertical direction, and two non-contact displacement sensors are mounted on said two three dimension movement fine tuning mechanisms respectively.

Abstract: Disclosed is a condenser microphone chip, comprising: a substrate (21); a diaphragm (26) spaced from the substrate; a curved beam (27) connected with the diaphragm (26) to anchor the diaphragm (26) to the substrate (21); a curved beam connecting part (29) having a shape of a substantially circular plate. The curved beam (27) is arranged in the diaphragm (26). The curved beam (27) includes a plurality of sub beams, each of the plurality of sub beams including a first sub beam portion extending in a substantially radial direction from a circumference of the curved beam connecting part (29); a second sub beam portion extending in a substantially circumferential direction from an end of the first sub beam portion away from the circumference of the curved beam connecting part (29) and having a shape of a substantial arc; and a third sub beam portion extending in the radial direction from an end of the second sub beam portion away from the first sub beam portion and connected to the diaphragm (26).

Abstract: Disclosed is a condenser microphone chip, comprising: a substrate (21); a diaphragm (26) spaced from the substrate; a curved beam (27) connected with the diaphragm (26) to anchor the diaphragm (26) to the substrate (21); a curved beam connecting part (29) having a shape of a substantially circular plate. The curved beam (27) is arranged in the diaphragm (26). The curved beam (27) includes a plurality of sub beams, each of the plurality of sub beams including a first sub beam portion extending in a substantially radial direction from a circumference of the curved beam connecting part (29); a second sub beam portion extending in a substantially circumferential direction from an end of the first sub beam portion away from the circumference of the curved beam connecting part (29) and having a shape of a substantial arc; and a third sub beam portion extending in the radial direction from an end of the second sub beam portion away from the first sub beam portion and connected to the diaphragm (26).