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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