Colour-shifting electronic skin could optimise wearables

27th July 2017
Posted By : Enaie Azambuja
Colour-shifting electronic skin could optimise wearables

The ability of some animals, including chameleons, octopus, and squid, to change their skin colour for camouflage, temperature control, or communication is well known. While science has been able to replicate these abilities with artificial skin, the colour changes are often only visible to the naked eye when the material is put under huge mechanical strain.

Now, however, researchers in China have developed a type of user-interactive electronic skin, with a colour change perceptible to the human eye, and achieved with a much-reduced level of strain. Their results could have applications in robotics, prosthetics and wearable technology.

Published in the journal 2D Materials, the study from Tsinghua University in Beijing, employed flexible electronics made from graphene, in the form of a highly-sensitive resistive strain sensor, combined with a stretchable organic electrochromic device.

Lead author Dr Tingting Yang, from Tsinghua University, said: "We explored the substrate (underlying) effect on the electromechanical behaviour of graphene. To obtain good performance with a simple process and reduced cost, we designed a modulus-gradient structure to use graphene as both the highly sensitive strain-sensing element and the insensitive stretchable electrode of the ECD layer.

"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."

Senior author Professor Hongwei Zhu said: "Graphene, with its high transparency, rapid carrier transport, flexibility and large specific surface area, shows application potential for flexible electronics, including stretchable electrodes, supercapacitor, sensors, and optical devices.

"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 said: "It's important to note that the capability we found for interactive colour 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."

You must be logged in to comment

Write a comment

No comments

More from Tsinghua University

Sign up to view our publications

Sign up

Sign up to view our downloads

Sign up

Factories of the Future Expo 2018
28th February 2018
United Kingdom Manchester
Embedded Systems and MtoM & Objets Connectés
21st March 2018
France Paris expo Porte de Versailles
ICMIM 2018
16th April 2018
Germany Munich
IoT Tech Expo 2018
18th April 2018
United Kingdom Olympia, London
The Security Event 2019
9th April 2019
United Kingdom NEC, Birmingham