Engineers invent octopus-inspired technology that can deceive and signal

With a split-second muscle contraction, the large blue-ringed octopus can change the size and color of the namesake patterns on its skin for purposes of deception, camouflage and signaling. Researchers at the University of California, Irvine were inspired by this natural wonder to develop a technology platform with similar capabilities that can be used in a variety of fields, including military, medicine, robotics and sustainable energy.

According to its inventors, the new devices made possible by this innovation will benefit from dynamically tunable fluorescent and spectroscopic properties, ease of manufacturing and the potential to expand to areas large enough to cover vehicles, panels, etc. displays and even buildings. Bio-inspired creation is the subject of a study published in Natural communications.

Hapalochlaena lunulata is a species of octopus native to the western Pacific Ocean and the Indian Ocean. It uses a neurotoxin venom to stun its prey and can ward off predators with its blue rings. It was these iridescent circles on a brown background on the creature’s skin that attracted the attention of UCI researchers.

“We are fascinated by the mechanisms underlying the blue-ringed octopus’ ability to rapidly change its skin markings between hidden and exposed states,” said co-senior author Alon Gorodetsky, professor of chemical and biomolecular engineering at the UCI.

“For this project, we worked to mimic the natural abilities of the octopus with devices made from unique materials that we synthesized in our laboratory. The result is an octopus-inspired deception and signaling system that is simple to manufacture and which works for a long time when used continuously, and can even repair itself when damaged.

The architecture of the innovation requires a thin film consisting of wrinkled blue rings surrounding brown circles, much like those of the octopus, sandwiched between a transparent proton-conducting uppermost electrode and an underlying acrylic membrane , with another identical electrode underneath.

Researchers developed their technical creativity at the molecular level when they explored the use of acenes, organic compounds consisting of linearly fused benzene rings. According to Gorodetsky, nonacene molecules (with nine linearly fused rings) used by the team help give the platform some of its exceptional capabilities.

“For our devices, we conceptualized and designed a nonacene-like molecule with a unique architecture,” said co-lead author Preeta Pratakshya, who recently received her Ph.D. at the UCI Department of Chemistry.

“Acenes are organic hydrocarbon molecules with a multitude of advantageous characteristics, including ease of synthesis, tunable electronic characteristics, and controllable optical properties.”

She added: “Our nonacene molecules are exceptional among acenes because they can survive years of storage in air and more than a day of continuous irradiation with bright light in air. No other expanded acene displays this combined long-term stability under such harsh conditions. “.

According to Gorodetsky, the type of molecules used to make the layer of colored blue rings gives the devices their most favorable characteristics, including tunable spectroscopic properties, facilitation of simple benchtop fabrication, and stability of the ambient atmosphere under lighting.

“Our co-author Sahar Sharifzadeh, professor of electrical and computer engineering at Boston University, demonstrated that the properties of stimuli-responsive molecules can be computationally predicted, paving the way for in silico design of other camouflage technologies,” Gorodetsky said.

In their lab tests, many of which took place at UCI’s California Institute of Telecommunications and Information Technology, the team found that the bioinspired devices could change their visible appearance more than 500 times with little to no degradation, and that they could also self-repair autonomously without user intervention. intervention.

The invention was shown to possess a desirable combination of capabilities in the ultraviolet, visible and near-infrared portions of the electromagnetic spectrum, according to Gorodetsky. This would allow devices to conceal other objects from detection or surreptitiously signal to observers.

“The photophysical robustness and general processability of our nonacene-like molecule – and likely its variants – open opportunities for future research on these compounds in the context of traditional optoelectronic systems such as light-emitting diodes and solar cells,” he said. added Gorodetsky.

Joining Gorodetsky and Pratakshya in this study were Chengyi Xu, Panyiming Liu, Reina Kurakake, and Robert Lopez of the UCI Department of Materials Science and Engineering; David Josh Dibble and Anthony Burke of the UCI Department of Chemical and Biomolecular Engineering; Philip Denison of the UCI Department of Chemistry; and Aliya Mukazhanova and Sharifzadeh of Boston University.