Liquid metal sticks to surfaces without a binding agent

Date:
June 9, 2023
Source:
Cell Press
Summary:
Everyday materials such as paper and plastic could be transformed
into electronic 'smart devices' by using a simple new method to
apply liquid metal to surfaces, according to scientists. The study
demonstrates a technique for applying a liquid metal coating to
surfaces that do not easily bond with liquid metal. The approach
is designed to work at a large scale and may have applications in
wearable testing platforms, flexible devices, and soft robotics.


Facebook Twitter Pinterest LinkedIN Email

==========================================================================
FULL STORY ========================================================================== Everyday materials such as paper and plastic could be transformed
into electronic "smart devices" by using a simple new method to apply
liquid metal to surfaces, according to scientists in Beijing, China. The
study, published June 9 in the journal Cell Reports Physical Science, demonstrates a technique for applying a liquid metal coating to surfaces
that do not easily bond with liquid metal. The approach is designed
to work at a large scale and may have applications in wearable testing platforms, flexible devices, and soft robotics.

"Before, we thought that it was impossible for liquid metal to adhere
to non- wetting surfaces so easily, but here it can adhere to various
surfaces only by adjusting the pressure, which is very interesting,"
said Bo Yuan, a scientist at Tsinghua University and the first author
of the study.

Scientists seeking to combine liquid metal with traditional materials
have been impeded by liquid metal's extremely high surface tension, which prevents it from binding with most materials, including paper. To overcome
this issue, previous research has mainly focused on a technique called "transfer printing," which involves using a third material to bind the
liquid metal to the surface.

But this strategy comes with drawbacks -- adding more materials can
complicate the process and may weaken the end product's electrical,
thermal, or mechanical performance.

To explore an alternative approach that would allow them to directly print liquid metal on substrates without sacrificing the metal's properties,
Yuan and colleagues applied two different liquid metals (eGaln and BilnSn)
to various silicone and silicone polymer stamps, then applied different
forces as they rubbed the stamps onto paper surfaces.

"At first, it was hard to realize stable adhesion of the liquid metal
coating on the substrate," said Yuan. "However, after a lot of trial and
error, we finally had the right parameters to achieve stable, repeatable adhesion." The researchers found that rubbing the liquid metal-covered
stamp against the paper with a small amount of force enabled the metal
droplets to bind effectively to the surface, while applying larger
amounts of force prevented the droplets from staying in place.

Next, the team folded the metal-coated paper into a paper crane,
demonstrating that the surface can still be folded as usual after the
process is completed.

And after doing so, the modified paper still maintains its usual
properties.

While the technique appears promising, Yuan noted that the researchers
are still figuring out how to guarantee that the liquid metal coating
stays in place after it has been applied. For now, a packaging material
can be added to the paper's surface, but the team hopes to figure out
a solution that won't require it.

"Just like wet ink on paper can be wiped off by hand, the liquid metal
coating without packaging here also can be wiped off by the object it
touches as it is applied," said Yuan. "The properties of the coating
itself will not be greatly affected, but objects in contact may be
soiled." In the future, the team also plans to build on the method
so that it can be used to apply liquid metal to a greater variety of
surfaces, including metal and ceramic.

"We also plan to construct smart devices using materials treated by this method," said Yuan.

This work was supported by China Postdoctoral Science Foundation, the
National Nature Science Foundation of China, and the cooperation funding between Nanshan and Tsinghua SIGS in science and technology.

* RELATED_TOPICS
o Computers_&_Math
# Spintronics_Research # Computer_Science #
Mobile_Computing # Mathematics
* RELATED_TERMS
o Industrial_robot o Cryptography o Cyber-bullying
o Virtual_reality o User_interface_design o
Introduction_to_quantum_mechanics o Computing_power_everywhere
o Robot

========================================================================== Story Source: Materials provided by Cell_Press. Note: Content may be
edited for style and length.


========================================================================== Journal Reference:
1. Bo Yuan, Xuyang Sun, Qianyu Wang, Hongzhang Wang. Direct
fabrication of
liquid-metal multifunctional paper based on force-responsive
adhesion.

Cell Reports Physical Science, 2023 DOI: 10.1016/j.xcrp.2023.101419 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/06/230609160620.htm

--- up 1 year, 14 weeks, 4 days, 10 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)