Researchers in China have developed a chameleon-like electronic skin capable of changing colour, which could be used in prosthetics and wearable tech.
The technology, created from graphene – a material 200 times stronger than steel – mimics the natural ability of squid, octopus and chameleons to change their skin shade to communicate and for camouflage.
The light, flexible and transparent nature of the material is a major improvement on previous attempts to create artificial electronic skin, in which colour changes could only be seen when the material was highly strained – in some cases, up to 500%.
This latest “user-interactive” development is capable of visibly changing colour, with a much-reduced level of pressure to the material – up to 10%.
The skin was made by combining two layers of graphene – a highly sensitive resistive strain sensor, and a stretchable organic electrochromic device (ECD).
Lead author of the study, Dr Tingting Yang, from Tsinghua University, said: “We explored the underlying effect on the electromechanical behaviour of graphene.
“We found subtle strain – between zero and 10% – was enough to cause an obvious colour change, and the RGB value of the colour quantified the magnitude of the applied strain.”
Professor Hongwei Zhu, senior author of the study published in the journal 2D Materials, said: “Graphene, with its high transparency, rapid carrier transport, flexibility and large specific surface area, shows application potential for flexible electronics.
“However, our results also show that the mechanical property of the substrate was strongly relevant to the performance of the strain sensing materials.
“This is something that has previously been somewhat overlooked but that we believe should be closely considered in future studies of the electromechanical behaviour of certain functional materials.”
Dr Yang added: “This user-interactive e-skin should be promising for applications in wearable devices, robots and prosthetics in the future.”