A report in the Research & Innovation section of Rutgers Today announces a new artificial muscle invention that can change color when exposed to light.

The engineers reference the chromatophores in octopuses and cuttlefish as inspiration for their project. Chromatophores are pigment-containing cells in species including amphibians, fish, reptiles, crustaceans and cephalopods. Any birds and animals have cells that contain pigment.

The engineers produced a sophisticated hydrogel that is 3D printable. The gel can alter its internal structure depending on the amount of light in the area. Hydrogels, which maintain their form and remains strong even though they are filled with water, are already used in the human body, Jell-O, diapers and contact lenses, among several other instances.

Photo by Mark Boss / Unsplash

“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.”

In addition to being able to contract in reaction to shifts in light, the "nanostream gel" consisting of nanostructured hydrolyzed collagen that has nanostructured aluminioparticles (NAP) inserted serving as an artificial muscle. The light-sensing smart gel, coupled with the 3D-printed stretchy plastic, switches colour, resulting in a camouflage effect.

The next measures would concentrate on enhancing the technology's sensitivity, reaction time, scalability, packaging and reliability.