An international team of researchers has developed a technique that uses liquid metal to create an elastic material that is impervious to both gases and liquids. Applications for the material include use as packaging for high-value technologies that require protection from gases, such as flexible batteries.
"This is an important step because there has long been a trade-off between elasticity and being impervious to gases," says
"Basically, things that were good at keeping gases out tended to be hard and stiff. And things that offered elasticity allowed gases to seep through. We've come up with something that offers the desired elasticity while keeping gases out."
The new technique makes use of a eutectic alloy of gallium and indium (
The researchers tested the effectiveness of the new material by assessing the extent to which it allowed liquid contents to evaporate, as well as the extent to which it allowed oxygen to leak out of a sealed container made of the material.
"We found that there was no measurable loss of either liquid or oxygen for the new material," says
The researchers are also conscious of costs associated with manufacturing the new material.
"The liquid metals themselves are fairly expensive," Deng says. "However, we're optimistic that we can optimize the technique - for example, making the
The researchers are currently exploring testing options to determine whether the material is actually an even more effective barrier than they've been able to show so far.
"Basically, we reached the limit of the testing equipment that we had available," Dickey says.
"We're also looking for industry partners to explore potential applications for this work. Flexible batteries for use with soft electronics is one obvious application, but other devices that either use liquids or are sensitive to oxygen will benefit from this technology."
The paper, "Liquid Metal-Based Soft and Hermetic Seals for Stretchable Systems," is published in the journal Science. Co-first authors of the paper are
The work was done with support from the
-shipman-
Note to Editors: The study abstract follows.
"Liquid Metal-Based Soft and Hermetic Seals for Stretchable Systems"
Authors:
Published:
DOI: 10.1126/science.ade734
Abstract: Soft materials tend to be highly permeable to gases, making it difficult to create stretchable hermetic seals. With the integration of spacers, we demonstrate the use of liquid metals, which show both metallic and fluidic properties, as stretchable hermetic seals. Such soft seals are used in both a stretchable battery and a stretchable heat transfer system that involve volatile fluids, including water and organic fluids. The capacity retention of the battery was ~72.5% after 500 cycles, and the sealed heat transfer system showed an increased thermal conductivity of approximately 309 watts per meters-kelvin while strained and heated. Furthermore, with the incorporation of a signal transmission window, we demonstrated wireless communication through such seals. This work provides a route to create stretchable yet hermetic packaging design solutions for soft devices.
https://news.ncsu.edu
.
(C) 2023 M2 COMMUNICATIONS, source