Colorful gel gets its smarts from octopuses

Inspired by the color-changing skin of octopuses, engineers have created a 3D-printed smart gel that can change shape and color when exposed to light

Original source: Materials Today

Inspired by the color-changing skin of cuttlefish, octopuses and squids, engineers at Rutgers University have created a 3D-printed smart gel that changes shape when exposed to light. This allows the gel to act as ‘artificial muscle’, and may lead to new military camouflage, soft robotics and flexible displays.

The engineers also developed a 3D-printed stretchy material that can reveal colors when the light changes, according to a paper on this work in ACS Applied Materials & Interfaces.

Their invention is modeled after the amazing ability of cephalopods such as cuttlefish, octopuses and squids to change the color and texture of their soft skin for camouflage and communication. This is achieved by thousands of color-changing cells, called chromatophores, in their skin.

“Electronic displays are everywhere and despite remarkable advances, such as becoming thinner, larger and brighter, they’re based on rigid materials, limiting the shapes they can take and how they interface with 3D surfaces,” said senior author Howon Lee, an assistant professor in the Department of Mechanical and Aerospace Engineering in the School of Engineering at Rutgers University-New Brunswick. “Our research supports a new engineering approach featuring camouflage that can be added to soft materials and create flexible, colorful displays.”

The 3D-printed smart gel is based on a hydrogel, which is mainly composed of water but is still able to keep its shape and stay solid. Hydrogels are found in the human body, Jell-O, diapers and contact lenses, among many other examples.

The engineers incorporated a light-sensing nanomaterial into the hydrogel, turning it into an ‘artificial muscle’ that contracts in response to changes in light. When combined with the 3D-printed stretchy material, this light-sensing smart gel can also change color, resulting in a camouflage effect.

Next steps will include improving the technology’s sensitivity, response time, scalability, packaging and durability.