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January 21, 2021

Smart hydrogel uses light to change shape and color

Rutgers University engineers have developed a 3D printable hydrogel, or smart gel, that senses light and changes shape as a result. The engineers incorporated a light-sensing nanomaterial in the hydrogel, turning it into an “artificial muscle” that contracts in response to changes in light. The light-sensing smart gel, combined with the 3D-printed stretchy material, changes color, resulting in a camouflage effect.

Credit: National Science Foundation/Karson Productions


Hidden in plain sight.

I'm Bob Karson with the Discovery Files, from NSF -- the U.S. National Science Foundation.

(Sound effect: undersea sounds) Nature has provided octopi, squid and cuttlefish with some mind-blowing camo gear. The ability to change the color and texture of their skin to blend in with the surroundings. Now engineers at Rutgers have successfully re-created these abilities in a 3d-printed smart gel that changes shape when exposed to light and reveals colors when light changes.

The sea creatures do it with color-changing cells in their skin called Chromataphores. To copy those, the engineers start with a hydrogel. Think, Jell-O or soft contacts -- hydrogels keep their shape and stay solid and flexible despite being filled with water.

This hydrogel is infused with a light-sensing nanomaterial, turning it into an artificial muscle that expands and contracts in response to light. That expands the stretchy material to reveal color for a camouflage effect.

Military camouflage and soft robotics could benefit from this. Electronic displays are another possible application because new materials allow for a more complete interface with existing surfaces.

(Sound effect: ratchet sound) The team is fine-tuning for sensitivity, response time, scalability, durability and packaging. A color-changing artificial muscle. (Sound effect: undersea sounds) Inspired by some elusive denizens of the deep.

Now, where's my octopus? He was just here.

"The discovery files" covers projects funded by the government's National Science Foundation. Federally sponsored research -- brought to you, by you! Learn more at nsf.gov or on our podcast.


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