A material that is identical to human skin in strength, stretchability and sensitivity could be used to collect biological data in real time, according to researchers.
A team of researchers at the King Abdullah University of Science and Technology have developed a durable ‘electronic skin’ that can mimic various natural functions of the human skin. It has been developed by reinforcing a substance called hydrogel with silica nanoparticles “as a strong and stretchy substrate and a 2D titanium carbide MXene as the sensing layer, bound together with highly conductive nanowires.”
E-skins are usually developed by layering an active nanomaterial on a stretchy surface that attaches to human skin and acts as a sensor. The connection between these layers however can be too weak at times which impacts the durability.
“The landscape of skin electronics keeps shifting at a spectacular pace,” explained KAUST postdoc Yichen Cai, one of the lead researchers. “The emergence of 2D sensors has accelerated efforts to integrate these atomically thin, mechanically strong materials into functional, durable artificial skins.”
“Hydrogels are more than 70 per cent water, making them very compatible with human skin tissues,” researcher Jie Shen further explained. This makes the material more stretchable and similar to the human skin.
The prototype e-skin built by the researchers could sense objects from 20 centimeters away. It could further respond to stimuli in less than one tenth of a second. The e-skin could also distinguish handwriting written upon it. “It is a striking achievement for an e-skin to maintain toughness after repeated use,” said Shen, “which mimics the elasticity and rapid recovery of human skin.”
Such e-skins when further developed have the potential to track a range of biological information including blood pressure fluctuations detected through vibrations in the arteries and movements of large limbs and joints. This data can then be stored on the cloud through Wi-fi.
“The ideal e-skin will mimic the many natural functions of human skin, such as sensing temperature and touch, accurately and in real time,” said Cai. “One remaining obstacle to the widespread use of e-skins lies in scaling up of high-resolution sensors,” added group leader Vincent Tung, “however, laser-assisted additive manufacturing offers new promise.”