• New technology 3D-prints glass microstru

    From ScienceDaily@1:317/3 to All on Wednesday, April 20, 2022 22:30:48
    New technology 3D-prints glass microstructures with rays of light
    The manufacturing technique enables faster production, greater optical
    quality and design flexibility

    Date:
    April 20, 2022
    Source:
    University of California - Berkeley
    Summary:
    Researchers have developed a new way to 3D-print glass
    microstructures that is faster and produces objects with higher
    optical quality, design flexibility and strength.



    FULL STORY ========================================================================== Researchers at UC Berkeley have developed a new way to 3D-print glass microstructures that is faster and produces objects with higher optical quality, design flexibility and strength, according to a new study
    published in the April 15 issue of the journal Science.


    ========================================================================== Working with scientists from the Albert Ludwig University of Freiburg,
    Germany, the researchers expanded the capabilities of a 3D-printing
    process they developed three years ago -- computed axial lithography (CAL)
    -- to print much finer features and to print in glass. They dubbed this
    new system "micro-CAL." Glass is the preferred material for creating
    complex microscopic objects, including lenses in compact, high-quality
    cameras used in smartphones and endoscopes, as well as microfluidic
    devices used to analyze or process minute amounts of liquid. But current manufacturing methods can be slow, expensive and limited in their ability
    to meet industry's increasing demands.

    The CAL process is fundamentally different from today's industrial
    3D-printing manufacturing processes, which build up objects from thin
    layers of material.

    This technique can be time-intensive and result in rough
    surface texture. CAL, however, 3D-prints the entire object
    simultaneously. Researchers use a laser to project patterns of light
    into a rotating volume of light-sensitive material, building up a 3D
    light dose that then solidifies in the desired shape. The layer-less
    nature of the CAL process enables smooth surfaces and complex geometries.

    This study pushes the boundaries of CAL to demonstrate its ability to
    print microscale features in glass structures. "When we first published
    this method in 2019, CAL could print objects into polymers with features
    down to about a third of a millimeter in size," said Hayden Taylor,
    principal investigator and professor of mechanical engineering at UC
    Berkeley. "Now, with micro-CAL, we can print objects in polymers with
    features down to about 20 millionths of a meter, or about a quarter
    of a human hair's breadth. And for the first time, we have shown how
    this method can print not only into polymers but also into glass, with
    features down to about 50 millionths of a meter." To print the glass,
    Taylor and his research team collaborated with scientists from the Albert Ludwig University of Freiburg, who have developed a special resin material containing nanoparticles of glass surrounded by a light- sensitive binder liquid. Digital light projections from the printer solidify the binder,
    then the researchers heat the printed object to remove the binder and
    fuse the particles together into a solid object of pure glass.

    "The key enabler here is that the binder has a refractive index that is virtually identical to that of the glass, so that light passes through
    the material with virtually no scattering," said Taylor. "The CAL printing process and this Glassomer [GmbH]-developed material are a perfect match
    for each other." The research team, which included lead author Joseph
    Toombs, a Ph.D. student in Taylor's lab, also ran tests and discovered
    that the CAL-printed glass objects had more consistent strength than
    those made using a conventional layer-based printing process. "Glass
    objects tend to break more easily when they contain more flaws or cracks,
    or have a rough surface," said Taylor. "CAL's ability to make objects
    with smoother surfaces than other, layer-based 3D-printing processes is therefore a big potential advantage." The CAL 3D-printing method offers manufacturers of microscopic glass objects a new and more efficient way
    to meet customers' demanding requirements for geometry, size and optical
    and mechanical properties. Specifically, this includes manufacturers of microscopic optical components, which are a key part of compact cameras, virtual reality headsets, advanced microscopes and other scientific instruments. "Being able to make these components faster and with more geometric freedom could potentially lead to new device functions or lower-
    cost products," said Taylor.

    This study was funded by the National Science Foundation, the European
    Research Council, the Carl Zeiss Foundation, the German Research
    Foundation and the U.S.

    Department of Energy.


    ========================================================================== Story Source: Materials provided by
    University_of_California_-_Berkeley. Original written by Marni
    Ellery. Note: Content may be edited for style and length.


    ========================================================================== Related Multimedia:
    * 3D-printed_glass_lattices ========================================================================== Journal Reference:
    1. Joseph T. Toombs, Manuel Luitz, Caitlyn C. Cook, Sophie Jenne,
    Chi Chung
    Li, Bastian E. Rapp, Frederik Kotz-Helmer, Hayden
    K. Taylor. Volumetric additive manufacturing of silica glass with
    microscale computed axial lithography. Science, 2022; 376 (6590):
    308 DOI: 10.1126/science.abm6459 ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2022/04/220420133522.htm

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