Inspired by the color-changing skin of cuttlefish, octopuses, and squids, engineers have created a 3D-printed smart gel that changes shape when exposed to light, becomes artificial muscle, and may lead to new military camouflage, soft robotics, and flexible displays. The team also developed a 3D-printed stretchy material that can reveal colors when light changes.
Their invention is modeled after the 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 the thousands of color-changing cells, called chromatophores, in their skin.
Electronic displays are based on rigid materials, limiting the shapes they can take and how they interface with 3D surfaces. The new approach features camouflage that can be added to soft materials to create flexible, colorful displays.
The team developed a 3D-printable hydrogel, or smart gel, that senses light and changes shape as a result. Hydrogels, which keep their shape and stay solid despite containing water, are found in the human body, diapers, and contact lenses, among many examples.
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.
Next steps include improving the technology’s sensitivity, response time, scalability, packaging, and durability.