Graphene enables color changing electronic skin

Researchers from Tsinghua University in China have developed a graphene-based user-interactive electronic skin, capable of changing color. The team made use of flexible electronics made from graphene, in the form of a highly-sensitive resistive strain sensor, combined with a stretchable organic electrochromic device.

To obtain good performance with a simple process and reduced cost, they designed a structure to use graphene as both the highly sensitive strain-sensing element and the insensitive stretchable electrode of the electric current density (ECD) layer.

"We found subtle strain - between zero and 10% - was enough to cause an obvious color change, and the RGB (red green blue) value of the color quantified the magnitude of the applied strain," said the researchers. However, results also show that the mechanical property of the substrate was strongly relevant to the performance of the strain sensing materials. "It's important to note that the capability we found for interactive color changes with such a small strain range has been rarely reported before. This user-interactive e-skin should be promising for applications in wearable devices, robots and prosthetics in the future," the team added.

In March 2017, a team at the University of Glasgow used graphene to develop a robotic hand with solar-powered skin, which may open the door to the development of prosthetic limbs or robots with a sense of touch.