e-Paper display technology in electronic devices reflects and draws upon the ambient light around you to display multiple colors, contrasts, and diffusion in communicating text and images. This technology has been evolving over the past couple of decades.
But biological organisms have been evolving color-changing abilities for millions of years. From the chameleon and cuttlefish to the octopus and squid, they have developed for adaptive concealment with camouflage and communication signaling display with warning or mating cues. Could we maybe learn something from them? After all, e-Paper devices lag in optical performance, particularly color generation.
That is why a team of researchers has produced a study aimed at helping biologists who work with these color-changing creatures as well as engineers working with e-Paper technology. The paper, titled Biological vs. Electronic Adaptive Coloration: How Can One Inform the Other?, in “The Journal of The Royal Society Interface”, had three goals, according to Eric Kreit, University of Cincinnati doctoral graduate,
“to allow display engineers to learn from millions of years of natural selection and evolution. To teach biologists the most advanced mechanisms and performance measurements used in human-made reflective e-Paper and to give all scientists a clearer picture of the long-term prospects for capabilities such as adaptive concealment and what can be learned from now you see me, now you don’t mechanisms.”
How Animals and E-Paper are Similar
One of the key findings is that there are various approaches for changing the reflective color of a surface, and that the highest-performance ones developed by both humans and nature share common features. They both use pigments, and they both change or attain color expression by spreading or compacting the pigment. Muscle fiber is used by animals to spread or compact pigment, and electronics use an electric field to.
On the other hand, even if the basic concept for color change is similar, modern technology has never developed anything near the complexity or sophistication of the biology and physics of cephalopod skin. Cephalopods are a varied branch of ocean dwellers and include 700 species of cuttlefish, squid and octopus. They are also the known masters of color change on our planet.
“The highest performance human-made approaches have been only recently developed, well after numerous other approaches were tried. Perhaps in the past, if we had more closely trusted nature’s ability to find the best solution, we would be further along today in creating better display technology,”
according to Jason Heikenfeld, University of Cincinnati associate professor of electronic and computing systems.
Biological Mastery of Ambient Light
Biological organisms that change color are highly efficient at using ambient light. Just have a look at the chameleon. Either the animal’s skin reflects light to achieve a bright-color effect, or it absorbs light to achieve stunning, multi-colored effects.
In their use of available light, biological organisms are more efficient than electronic devices, which generally require large amounts of electric power to generate an internal or emissive light to generate bright colors.
“Cephalopod skin is exquisitely beautiful and radiant, and can be changed in milliseconds, all without generating any intrinsic light from within the skin; there are elegant solutions from biology waiting to be translated to our consumer and industrial world,”
says Roger T. Hanlon, a research scientist at the Marine Biological Laboratory in Woods Hole, Mass.
Indeed, overall, animals outperform synthetic devices when it comes to sophistication and integrated systems; required energy use for color change; size scalability (cephalopods’ adaptive coloration works over a wide range of sizes in the organisms’ class – from small-size cuttlefish to large-size octopus and squid); and surface texture (cephalopods can selectively adapt or “crinkle” their skins to match a variety of three-dimensional textures, which provides additional light scattering and shadowing).