Thermal vision cameras detect differences in temperature by sensing infrared wavelengths. If a coating could be developed that showed dynamic tuning of the effective temperature, it might be possible to hide objects from infrared sensing. By drawing inspiration from squid skin, Professor Alon Gorodetsky and his colleagues at the University of California, Irvine developed adaptive infrared-reflecting structures that feature robust mechanical properties, fast response, low working temperature, tunable spectral range, weak angular dependence etc.
Xu et al achieved a breakthrough, inventing a stretchy new material modeled after both squid skin and Hollywood dinosaurs with remarkable properties. Image credit: Xu et al, doi: 10.1126/science.aar5191.
Products that reflect heat, such as emergency blankets, have existed for decades.
But in the past several years, researchers have pushed to create dramatically improved versions via bio-inspired engineering.
One focus has been to imitate how squid and other cephalopods can nearly instantaneously change their skin to blend into their surrounding environment.
Now, Professor Gorodetsky and co-authors have done it, creating prototypes that can next be scaled up into large sheets of commercially useable material.
“Basically, we’ve invented a soft material that can reflect heat in similar ways to how squid skin can reflect light,” Professor Gorodetsky said.
“It goes from wrinkled and dull to smooth and shiny, essentially changing the way it reflects the heat.”
Potential uses include better camouflage for troops and insulation for spacecraft, storage containers, emergency shelters, clinical care, and building heating and cooling systems.
“We were inspired both by science fiction and science fact — seeing dinosaurs disappear and reappear under an infrared camera in ‘Jurassic World’ and seeing squid filmed underwater do similar things,” Professor Gorodetsky said.
“So we decided to merge those concepts to design a really unique technology.”
Made of sandwiches of aluminum, plastic, and sticky tape, the new material transforms from a wrinkled grey to a glossy surface when it is either pulled manually or zapped with voltage.
“It was hard, especially the first phase when we were learning how to work with the sticky material,” said Chengyi Xu, a doctoral student at the University of California, Irvine.
“After trial-and-error processes involving thousands of attempts, we finally saw the mirror-like coating change when they pulled it sideways.”
The team’s results are published in the journal Science.
_____
Chengyi Xu et al. 2018. Adaptive infrared-reflecting systems inspired by cephalopods. Science 359 (6383): 1495-1500; doi: 10.1126/science.aar5191
