In a new study, researchers have examined parallels between e-Paper technology – the technology behind sunlight-readable devices like the Kindle – and biological organisms that change colour.
Over millions of years, biological organisms – from the chameleon and cuttlefish to the octopus and squid – have developed colour-changing abilities for adaptive concealment and communication signalling like warning or mating cues.
Over the past two decades, humans have begun to develop sophisticated e-Paper technology in electronic devices that reflect and draw upon the ambient light around you to create multiple colours, contrast and diffusion to communicate text and images.
And given the more than 100 million years head start that evolution has provided to these animals and their cellular systems, it’s not surprising that e-Paper devices lag behind in optical performance, especially colour generation.
In an effort to close that gap, a multidisciplinary team led by University of Cincinnati researchers aims to help biologists who work with these colour-changing creatures and engineers who work with e-Paper technology.
“Our main goals were threefold: 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,” Eric Kreit, co-author of the study, said.
One of the researchers’ key findings is that there are numerous approaches to change the reflective colour of a surface and that the highest-performance approaches developed by both humans and nature share some powerful common features.
Both use pigment, and both change or achieve colour expression by either spreading or compacting that pigment. Animals use muscle fibre to spread or compact pigment, and electronics make use of an electric field to do so.
However, even if the basic approach for colour change is similar, humanity has never developed anything as complex or sophisticated as the biology and physics of cephalopod skin.
“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,” Jason Heikenfeld said.
Biological organisms that change colour are very efficient at using available light. The animal’s skin either reflects light to achieve a bright-colour effect or absorbs light to achieve stunning, multi-coloured effects.
In their use of available light, the 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 colour.
Human-developed technology is far superior to cephalopods or other colour-adapting animals when it comes to speed. In other words, human-made electronics can achieve colour and a colour change faster than the response time of a biological organism.
In addition, synthetic devices can provide a greater range of colours and more efficient dark or black state. In other words, a device can achieve a black screen, but most biological organisms cannot achieve such darkened colouring.
This is, in part, due to the fact that an organism like a marine animal generally has no reason, in terms of survival adaptation or signalling, to go to a dark or black state. Such an adaptation would actually make them more visible, not less, to predators.
The study has been published online in The Journal of The Royal Society Interface.