Momentum - The Magazine for Virginia Tech Mechanical Engineering Vol. 3 No. 4 Winter 2018 | Page 16

STORY BY ANDREW TIE
MACROMOLECULES INNOVATION INSTITUTE
Researchers expand
breakthroughs in 3D
printing Kapton, the
'ultimate' polymer
An interdisciplinary team of researchers at Virginia Tech's Macromolecules Innovation
Institute (MII) have developed a new process to 3D print one of the most-desired materials in
the electronics and aerospace industries.
The material, commonly known by its trade name Kapton, is a polyimide with exceptional
thermal and electrical properties. Kapton has a degradation temperature around 550 degrees
Celsius, doesn't dissolve in solvents, acts as an electrical insulator, and is resistant to ultraviolet
irradiation. Because the molecule is all-aromatic, containing rings that restrict rotation, Kapton
is also very stable.
"(Kapton) can withstand all kinds of harsh environmental insults: radiation, high tempera-
ture, chemical reagents," said Timothy Long, a professor of chemistry, the director of MII, and
one of the researchers in the study. "It's one of these molecules that is the ultimate in terms of
performance."
Kapton was previously available only in thin 2D sheets and is known as the basis for the "gold
foil" that wraps around satellites to insulate them.
But last year, Long and other collaborators in the College of Science and the College of
Engineering discovered a path to 3D printing Kapton for the first time using a process called
stereolithography.
The researchers, from the Long Group in the Department of Chemistry and the Design, Re-
search, and Education for Additive Manufacturing Systems (DREAMS) Lab in the Department
of Mechanical Engineering, have now found a second way to 3D print Kapton. This process,
called direct ink write (DIW), was detailed in a recent article in ACS Applied Materials & Inter-
faces. The researchers now have greater flexibility in incorporating Kapton into manufacturing
processes.
"If you think of caulking a bathtub or decorating a cake with icing, (DIW is) a very similar
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FALL 2018
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