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Inspired by the real-life pattern-changing abilities of the greater blue-ringed octopus, the system was developed by researchers at the University of California, Irvine (UCI).
With a split-second muscle contraction, the marine animal – native to the Western Pacific Ocean and Indian Ocean – can change the size and colour of the patterns on its skin for deception, camouflage and signalling. It uses a neurotoxin venom to stun its prey, and can ward off predators with a flash of its blue rings.
Researchers drew inspiration from the octopus to develop a technological platform with similar capabilities, which could be used in the military, medicine, robotics and sustainable energy.
According to its inventors, new devices made possible by the innovation will benefit from “dynamically adjustable fluorescent and spectroscopic properties, ease of manufacturing, and potential for scaling”.
Professor Alon Gorodetsky, senior co-author of a paper on the work, said: “We are fascinated by the mechanisms underpinning the blue-ringed octopus’ ability to rapidly switch its skin markings between hidden and exposed states.
“For this project, we worked to mimic the octopus’ natural abilities with devices from unique materials we synthesized in our laboratory, and the result is an octopus-inspired deception and signalling system that is straightforward to fabricate, functions for a long time when operated continuously, and can even repair itself when damaged.”
The system includes a thin film of wrinkled blue rings surrounding brown circles – much like those on the octopus – sandwiched between a transparent proton-conducting electrode and an underlying acrylic membrane, with another identical electrode underneath.
On the molecular level, the researchers explored the use of acenes, organic compounds made of linearly fused benzene rings. Nonacene-like molecules (meaning they have nine linearly fused rings) helped give the platform some of its “outstanding” capabilities, said Professor Gorodetsky.
The molecules used to fabricate the coloured blue ring layer are what give the devices their most favourable features, he added, including adjustable spectroscopic properties, the facilitation of straightforward benchtop manufacturing, and ambient-atmosphere stability under illumination.
In laboratory tests, the team found that the bioinspired devices could change their visible appearance over 500 times with little or no degradation, and they also could autonomously self-repair without user intervention.
The invention possesses a “desirable” combination of capabilities in the ultraviolet, visible light, and near-infrared parts of the electromagnetic spectrum, according to Professor Gorodetsky. This could enable devices to disguise other objects from detection, or to clandestinely signal to observers.
The work was published in Nature Communications.
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