Research into how light can affect material shape goes deep—rather, into the depths—by drawing inspiration from cephalopods: marine animals including squids, octopuses and cuttlefish that can change their shape and color.
Cells called chromatophores allow these many-armed mollusks to change their skin texture to better blend in with the environment to avoid predators and hide from their own prey. New research from CU Boulder focuses on how light can manipulate the shape of man-made materials by emulating these amazing cephalopods.
Gallogly Professor Timothy White of the Department of Chemical and Biological Engineering is the lead author of “Light Control with Liquid Crystalline Elastomers,” now appearing in Advanced Optical Materials, which explores this line of research.
“This work focused on the preparation of reflective polymeric materials that change color when heated,” White said. “We then show that by laminating this color-changing layer with a shape-changing layer—similar to tissues in the cephalopod—we can create polymer films that change shape and color.”
White and his collaborators employ the thermal response of liquid crystalline elastomers—materials that are soft, like rubber bands, and are arranged with a technique developed by White at the Air Force Research Laboratory and CU Boulder.
“We can effectively pixelate these liquid crystalline materials, similar to capturing a freeze frame of an image on your liquid crystal display in your television or cell phone,” he said. “The complex organization of the material dictates the shape change and allows us to reconfigure the topography of these materials.”
White wants to explore how these materials could be applied in the photonics industry. Photonics products include lasers, screens and displays, fiber optic cables, scanners and more.
This project began during White’s time at the Air Force Research Laboratory with Michelle Brannum, a graduate student at Case Western Reserve University. White advised Brannum through a Department of Defense SMART Fellowship.
“This has been a fun project to work on with her and her advisors at Case Western and we are grateful to the Department of Defense for funding her fellowship through the SMART Program,” he said.
White plans to explore partnerships in using the light control of these materials as color-changing sensors in packaging or energy management applications, and is actively submitting proposals to extend the research.
"Through future study, we hope to further understand how far we can push the color change of these materials, as well as explore ways in which we can locally control it."