Electronic skin or e-skin, may play an important role in next-generation prosthetics, personalised medicine, soft robotics and artificial intelligence (AI), say researchers.
Electronic skin is a material that mimics human skin in strength, stretchability and sensitivity could be used to collect biological data in real-time.
“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 study author Yichen Cai from the King Abdullah University of Science and Technology in Saudi Arabia.
“However, making suitably flexible electronics that can perform such delicate tasks while also enduring the bumps and scrapes of everyday life is challenging, and each material involved must be carefully engineered,” Cai added.
Most e-skins are made by layering an active nanomaterial (the sensor) on a stretchy surface that attaches to human skin.
However, the connection between these layers is often too weak, which reduces the durability and sensitivity of the material; alternatively, if it is too strong, flexibility becomes limited, making it more likely to crack and break the circuit.
“The landscape of skin electronics keeps shifting at a spectacular pace. The emergence of 2D sensors has accelerated efforts to integrate these atomically thin, mechanically strong materials into functional, durable artificial skins,” Cai said.
The ream has now created a durable e-skin using a hydrogel reinforced 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.
“Hydrogels are more than 70 per cent water, making them very compatible with human skin tissues,” the researchers said.
By pre-stretching the hydrogel in all directions, applying a layer of nanowires, and then carefully controlling its release, the team created conductive pathways to the sensor layer that remained intact even when the material was stretched to 28 times its original size.
Their prototype e-skin could sense objects from 20 centimetres away, respond to stimuli in less than one-tenth of a second, and when used as a pressure sensor, could distinguish handwriting written upon it.
It continued to work well after 5,000 deformations, recovering in about a quarter of a second each time.
“It is a striking achievement for an e-skin to maintain toughness after repeated use, which mimics the elasticity and rapid recovery of human skin,” the team wrote.
Earlier, another study, published in the journal Advanced Intelligent Systems, reported that researchers from RMIT University in Australia developed electronic artificial skin that reacts to pain just like real skin, opening the way to better prosthetics, smarter robotics and non-invasive alternatives to skin grafts. (IANS)
