Laboratory test tubes – CSIC – ARCHIVE
MADRID, 30 November (EUROPA PRESS) –
Researchers at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia have developed a material that mimics human skin in terms of strength, stretch and sensitivity to collect biological data in real time. This “es-kin” can play an important role in next-generation prostheses, personalized medicine, soft robotics and artificial intelligence, scientists say in the journal Science Advances.
“The ideal electronic skin will mimic the many natural functions of human skin, such as temperature and touch detection, accurately and in real time,” says KAUST postdoc Yichen Cai.
However, making suitable and flexible electronic devices that can perform such delicate tasks while resisting swelling and scratches in everyday life is a challenge and every material involved must be carefully designed.
Most electronic skins are made by placing an active nanomaterial (sensor) on an elastic surface that adheres to human skin. However, the connection between these layers is often too weak, which reduces the durability and sensitivity of the material; on the other hand, if it is too strong, the flexibility becomes limited, which makes it more likely to break and break the circuit.
“The landscape of leather electronics continues to change at a spectacular pace,” said Cai. “The advent of 2D sensors has accelerated efforts to integrate these highly mechanical and atomic thin materials into functional and durable artificial leather.”
A team led by Cai and his colleague Jie Shen created a durable electronic skin using a hydrogel reinforced with silica nanoparticles as a strong and elastic substrate and an MXD 2D titanium carbide as a detection layer, bonded with highly conductive nanowires.
“Hydrogels contain over 70% water, which makes them very compatible with human skin tissues,” explains Shen. By stretching the hydrogel in all directions, applying a layer of nanowires and then carefully controlling their release, the researchers created conductive pathways to the sensor layer that remained intact even when the material was stretched 28 times the original size.
Its electronic skin prototype could detect objects at 8 inches away, respond to stimuli in less than a tenth of a second, and when used as a pressure sensor, could distinguish handwriting on it. It continued to function well after 5,000 deformations, recovering in about a quarter of a second each time.
“It is a surprising achievement for an electronic skin to maintain its hardness after repeated use – Shen points out – which mimics the elasticity and rapid recovery of human skin.”
Such electronic skins could monitor a variety of biological information, such as changes in blood pressure, which can be detected from vibrations in the arteries to the movements of large limbs and joints. This data can be shared and stored in the cloud via Wi-Fi.
“A remaining obstacle to the widespread use of electronic skins is the expansion of high-resolution sensors,” adds group leader Vincent Tung. “However, laser-assisted additive production offers new promises.”
“We have a future in mind for this technology beyond biology,” Cai continues. “The stretch sensor tape can one day monitor the structural health of inanimate objects, such as furniture and airplanes.”