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A newmaterial called “thubber” exhibits
both thermal conductivity and elasticity.
10 times as much force as concrete
before failure, and is just as hard to
deform as stone or concrete.
The cold sintering process could
be a boon in the quest for carbon neu-
trality. Captured carbon dioxide could
be used to produce the calcium car-
bonate nanopowder, and the ceramics
produced could serve as substitutes
for cement-based materials, which
currently require energy-intensive pro-
duction methods that generate large
amounts of CO
2
.
www.ethz.ch/en.NEW COMPOSITE IS A
STRETCH
Researchers at Carnegie Mellon
University, Pittsburgh, developed an
electrically insulating rubber material
that exhibits an unprecedented com-
bination of thermal conductivity and
elasticity. The key ingredient in the new
composite—nicknamed “thubber”—is
a suspension of nontoxic, liquid metal
microdroplets. The liquid state allows
the metal to deform with the surround-
ing rubber at room temperature. When
the rubber is pre-stretched, the drop-
lets form elongated pathways that are
efficient for heat travel. To demonstrate
these findings, the team mounted an
LED light onto a strip of the material to
create a safety lamp worn around a jog-
ger’s leg. The “thubber” dissipated the
heat from the LED, which would have
otherwise burned the jogger.
“Until now, high power devices
have had to be affixed to rigid, inflexi-
ble mounts that were the only technol-
ogy able to dissipate heat efficiently,”
explains Jonathan Malen, associate
professor of mechanical engineering.
The new material’s combination of
high thermal conductivity and elastic-
ity—it can stretch to six times its initial
length—is critical in applications such
as wearable computing and soft robot-
ics. Advanced manufacturing, energy,
and transportation are other areas
where stretchable electronic material
could have an impact.
cmu.edu.
Ceramic sample compacted at room
temperature. Courtesy of ETH Zurich/
Peter Rüegg.