The joy of sipping a hot coffee on a cold day is something different. You might have to thank a squid for giving you that pleasure in the future. Engineers at the University of California have drawn inspiration from cephalopod skin. They have invented an adaptive composite material that can not just insulate beverage cups but also keep restaurant to-go bags, shipping containers, and parcel boxes warm.
The innovation we are talking about is an
infrared-reflecting metalized polymer film which was developed in the
laboratory of Alon Gorodetsky, UCI associate professor of chemical and
biomolecular engineering. In a paper published recently in Nature Sustainability, Gorodetsky
and his team members described a large-area composite material that regulates
heat via reconfigurable metal structures that can reversibly separate and come
back together under different strain levels.
Gorodetsky stated, “The metal islands in
our composite material are next to one another when the material is relaxed and
become separated when the material is stretched, allowing for control of the
reflection and transmission of infrared light or heat dissipation. The
mechanism is analogous to chromatophore expansion and contraction in a squid’s
skin, which alters the reflection and transmission of visible light.”
Usually, chromatophore size changes help
squids communicate and camouflage their bodies to elude predators and hide from
prey. By mimicking this approach, Gorodetsky and his team have enabled “tunable
thermoregulation” in their material. It can improve energy efficiency and
protect sensitive fingers from hot surfaces, said Gorodetsky.
A project breakthrough happened when the
researchers developed a cost-effective production method of the composite
material at application-relevant quantities. The cost of raw materials like
rubber and copper is low as they start at around a dime per square meter. According
to the paper, even these costs will be lowered further by economies of scale.
The fabrication technique of the team
involves depositing a copper film onto a reusable substrate like aluminum foil
and then spraying multiple polymer layers onto the copper film. Thankfully, all
of this can be done in nearly any batch size.
Gorodetsky said, “The combined
manufacturing strategy that we have now perfected in our lab is a real game-changer.
We have been working with cephalopod-inspired adaptive materials and systems
for years but previously have only been able to fabricate them over relatively
small areas. Now there is finally a path to making this stuff roll-by-roll in a
factory.”
Mohsin Badshah, a former UCI postdoctoral
scholar in chemical and biomolecular engineering and the lead author, said that
the invention would be environmentally sustainable. Badshah said, “The composite
material can be recycled in bulk by removing the copper with vinegar and using
established commercial methods to repurpose the remaining stretchable polymer.”
Highlighting the potential applications,
Gorodetsky stated, “There is an enormous array of applications for this
material. Think of all the perishable goods that have been delivered to
people’s homes during the pandemic. Any package that Amazon or another company
sends that needs to be temperature-controlled can use a lining made from our
squid-inspired adaptive composite material. Now that we can make large sheets
of it at a time, we have something that can benefit many aspects of our lives.”
Sources:
https://www.newswise.com/articles/squid-skin-inspired-cup-cozy-will-keep-your-hands-cool-and-your-coffee-hot
https://news.uci.edu/2022/03/28/squid-skin-inspired-cup-cozy-will-keep-your-hands-cool-and-your-coffee-hot/
https://darik.news/california/squid-skin-inspired-cup-will-keep-your-hair-comfortable/202203558444.html