Abstract: Provided are a method for preparing a microfluidic device, a microfluidic device and a microfluidic system. The method includes: providing a mold having a groove; injecting a liquid metal into the groove of the mold, and solidifying the liquid metal to obtain a solid metal; separating the solid metal from the mold; providing the solid metal with an electrode; providing a cladding layer on a surface of the solid metal provided with the electrode, such that the solid metal is wrapped by the cladding layer, and at least a part of the electrode extends outside the cladding layer, so as to obtain a preform; and fixing the preform in a substrate, melting the solid metal and extending at least a part of the electrode outside the substrate, to obtain the microfluidic device.

Abstract: A laser transfer printing device and a laser transfer printing method are provided. The laser transfer printing device includes a laser, a beam expander, a beam splitter and a focusing module. The laser is configured to generate a laser beam. The beam expander is disposed on an optical path of the laser beam generated by the laser to expand the laser beam generated by the laser. The beam splitter is disposed on an optical path of the laser beam expanded by the beam expander to reflect the expanded laser beam to the focusing module. The focusing module is disposed on an optical path of the laser beam reflected by the beam splitter to focus the laser beam and project the focused laser beam to a predetermined transfer processing position.

Abstract: A polishing method for an inner wall of a hollow metal part, including: firstly, placing a coaxial cathode in an inner hole of a metal part when a metal part model is designed, and printing the metal part model and the coaxial cathode together; then, sealing two ends of an inner hole cavity of the metal part by using a light curing part, fixing the coaxial cathode, filling the cavity with a polishing solution, and performing polishing treatment by using an electrochemical polishing method; and finally, reversing an electrode to break the coaxial cathode and take out the broken coaxial cathode to obtain a polished metal part.

Abstract: A selective laser melting technology-based apparatus for preparing a gradient material, comprising a laser scanning array lens, and a powder storer, a powder mixer, a powder scraping plate, and a working platform that are provided in sequence from top to bottom; the powder storer is provided with two or more partitions; a bottom portion of the powder storer is provided with an outlet; the powder mixer is provided under the powder storer and is a horizontally provided rotational mixer; the powder scraping plate is disposed under the powder mixer; the working platform is provided under the powder scraping plate; the laser scanning array lens is provided on the working platform. The present invention further relates to a method for preparing a gradient material, comprising powder storing, powder scraping, powder mixing, powder laying, and printing. The method can guarantee the two-phase powder ratio in each layer of powder not change.

Abstract: A camera module and a mobile terminal are provided. The camera module includes a lens assembly, a light guide member and a light source, the light guide member is of an annular structure, and the light guide member is sleeved on an outer peripheral side of the lens assembly; and light emitted from the light source is incident in the light guide member through the outer peripheral side of the light guide member and is emitted out through a light emitting surface of the light guide member, and the light emitting surface faces toward an object side of the lens assembly. The camera module and the mobile terminal have sufficient and uniform illumination supplementation.

Abstract: A laser transfer printing device and a laser transfer printing method are provided. The laser transfer printing device includes a laser, a beam expander, a beam splitter and a focusing module. The laser is configured to generate a laser beam. The beam expander is disposed on an optical path of the laser beam generated by the laser to expand the laser beam generated by the laser. The beam splitter is disposed on an optical path of the laser beam expanded by the beam expander to reflect the expanded laser beam to the focusing module. The focusing module is disposed on an optical path of the laser beam reflected by the beam splitter to focus the laser beam and project the focused laser beam to a predetermined transfer processing position.

Abstract: Provided are a method for preparing a microfluidic device, a microfluidic device and a microfluidic system. The method includes: providing a mold having a groove; injecting a liquid metal into the groove of the mold, and solidifying the liquid metal to obtain a solid metal; separating the solid metal from the mold; providing the solid metal with an electrode; providing a cladding layer on a surface of the solid metal provided with the electrode, such that the solid metal is wrapped by the cladding layer, and at least a part of the electrode extends outside the cladding layer, so as to obtain a preform; and fixing the preform in a substrate, melting the solid metal and extending at least a part of the electrode outside the substrate, to obtain the microfluidic device.

Abstract: A polishing method for an inner wall of a hollow metal part, including: firstly, placing a coaxial cathode in an inner hole of a metal part when a metal part model is designed, and printing the metal part model and the coaxial cathode together; then, sealing two ends of an inner hole cavity of the metal part by using a light curing part, fixing the coaxial cathode, filling the cavity with a polishing solution, and performing polishing treatment by using an electrochemical polishing method; and finally, reversing an electrode to break the coaxial cathode and take out the broken coaxial cathode to obtain a polished metal part.