Color-changing skins inspired by squids created for robots to react without wires, screens

At the core of this development are structures that imitate chromatophores, which are pigment-filled sacs in the skin of squids, cuttlefish, and octopuses. These sacs become visible when small muscles pull on them, spreading the pigment and altering the animal’s appearance. The team’s synthetic version closely replicates this mechanism and functions as a dynamic color-changing skin.

“We are working in an emergent area sometimes called autonomous materials,” said Stephen Morin, associate professor of chemistry and lead author of a new study. “Autonomous materials have the ability to interact, sense and react with their environment in the absence of user input.”

Soft skins that sense, respond, and display information

The synthetic skins developed by Morin’s team are made of layers of microstructured, stretchable materials that can respond to different environmental stimuli. These artificial chromatophores can be programmed to change color in reaction to heat, light, or other physical triggers, just like their biological counterparts. The ability to respond without needing electronics or wires opens up wide possibilities in soft robotics, where flexibility and adaptability are key.

“These synthetically developed soft skins mimic the cephalopods’ color switching and led to the fabrication of stretchable arrays of microstructured, stimuli-responsive versions,” explained Morin.

The technology could also be used in human-machine interfaces. Imagine wearable devices that conform to the body and shift color to display environmental information—without rigid screens or power-hungry components. That’s the kind of future these materials could enable.

“It unlocks a lot of very interesting opportunities in soft robotics, new types of human machine interfaces,” the associate professor added.

These color-changing skins might eventually replace traditional displays in specific applications, especially where flexibility or water resistance is critical. Instead of needing LED screens or fixed components, soft materials could serve as real-time sensors or communicators.

“Imagine what a squid or an octopus can do in terms of creating patterns and doing so very rapidly and dynamically … but in an entirely synthetic structure,” said Morin, who is also part of the Nebraska Center for Materials and Nanoscience.

Real-world potential in wearables and wet environments

Graduate student Brennan Watts, a fourth-year PhD candidate in chemistry and a co-author on the paper, highlighted how tunable these materials are. By adjusting their chemical makeup, the skins can be made to react only to specific environmental conditions like pH, humidity, or temperature. This precision could be incredibly useful for creating wearable sensors that monitor multiple parameters at once.

“These types of devices are very versatile,” Watts said. “We can finely tune the chemistry of the individual components … and have materials that respond to very specific stimuli.”

“You could have a wearable technology that simultaneously reports the temperature, pH, humidity, all sorts of different parameters in a given environment. Doing that with traditional technologies, it would be challenging to measure all of those at the same time.”

One of the biggest strengths of these new materials is their versatility in different environments, especially wet or underwater settings, where standard electronics often fail. While Morin emphasizes that soft materials aren’t meant to replace traditional tech altogether, their unique properties allow them to function where rigid components can’t.

“The ‘soft materials’ technology will not completely replace current technologies,” he stated. “But their chemical and environmental versatility allows them to operate in different environments, particularly in aqueous settings.”

The study was published in the journal Advanced Materials.