June_AMP_Digital

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A D V A N C E D
M A T E R I A L S
&
P R O C E S S E S | J U N E
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Transmission electron microscopy image
of different levels of crystallinity in the
amorphous alloy. Courtesy of Jacobs
School of Engineering/UC San Diego.
touch sensitivity is in short supply. Xin-
Quan Zhang from the Singapore Insti-
tute of Manufacturing Technology
(A*Star) and colleagues are working
on a promising alternative—touch-
sensitive film, a printed, mesh-like pat-
tern of ultra-fine metal lines, created
using roll-to-roll gravure printing. This
method traditionally uses an etched
mold to transfer ink onto paper. Here,
the etched cylindrical mold transfers a
precise pattern of conductive metal ink
onto the touch-sensing substrate. Light
from the screen passes through the
holes in the printed mesh. Before this
study, the finest lines that could be
printed this way were ~50 μm wide,
which blocked more than a third of the
screen’s light. The team overcame this
limitation through diamond microen-
graving. Instead of using a laser to etch
the grid-like pattern of tiny inkwells into
the printer’s cylindrical mold, a tiny
diamond-tipped cutting tool to pattern
the roller using ultraprecision machin-
ing technology is used. .
IMPACT-RESISTANT STEEL
COULD PROTECT TROOPS
Researchers from the University
of California, San Diego, the University
of Southern California, and the Cali-
fornia Institute of Technology devel-
oped and tested a type of steel with a
record-breaking ability to withstand an
impact without deforming permanently.
The new steel alloy could be used in a
wide range of applications, fromdrill bits
to body armor to meteor-resistant sat-
ellite casings. The material is an amor-
phous steel alloy, a promising subclass
of steel alloys made of arrangements of
atoms that deviate from steel’s classical
A transparent printedmetal filmmay one
day coat smartphone screens. Courtesy
of Westend61/Getty.
crystal-like structure, where iron atoms
occupy specific locations.
Researchers believe their work on
the steel alloy, SAM2X5-630, is the first
to investigate how amorphous steels
respond to shock. SAM2X5-630 has the
highest recorded elastic limit for any
steel alloy, according to the research-
ers. It can withstand pressure and stress
up to 12.5 GPa or about 125,000 atmo-
spheres without undergoing perma-
nent deformation. .