Prosthetics hope synthetic leather “can repair itself 5,000 times”

Strong, supple and sensitive synthetic leather that can repair itself up to 5,000 times has been developed and could be used in future prosthetics, experts say.

Known as “electronic skin” or “electronic skin”, it was developed by researchers at King Abdullah University of Science and Technology in Saudi Arabia.

The team says skin could in the future be used to monitor a person’s health or the structural condition of an aircraft, as it is as sensitive as human skin.

While this isn’t the first time scientists have tried to “electronically” replicate human skin, previous attempts have failed to reach the real deal.

This prototype can detect objects from up to eight inches away, react to things in less than a tenth of a second, and repair itself more than 5,000 times.

Study author Dr Yichen Cai said the ideal e-skin should mimic the many natural functions of human skin, including sensing temperature and touch, in real time.

“However, making adequately flexible electronic components that can perform such delicate tasks while at the same time withstanding the bumps and scratches of everyday life is challenging and every material involved must be carefully designed,” explained Cai.

Previous attempts to copy human skin combined a sensor layer, made up of an active nanomaterial, with an elastic layer that attaches to our skin.

But the connection between these two layers is often too weak or too strong, reducing its durability, sensitivity or flexibility, which makes it more likely to break.

Dr Cai said, “The skin electronics landscape continues to change at a spectacular rate.

“The emergence of 2D sensors has accelerated efforts to integrate these atomically thin and mechanically strong materials into functional and durable artificial leathers.”

To solve this problem, the researchers used a silica nanoparticle-reinforced hydrogel to create their “elastic surface” and combined it with a 2D titanium carbide MXene sensor using highly conductive nano wires.

Co-author Dr Jie Shen said, “Hydrogels contain more than 70% water, making them very compatible with human skin tissues.

They found that by pre-stretching the hydrogel in all directions, then applying a layer of nanowires and controlling its release, they created pathways for the sensor layer that remained intact even as the material stretched up to 28 times its size. original.

Their prototype e-skin can detect objects eight inches away and respond to stimuli in less than a tenth of a second, the researchers say.

At the same time it is highly sensitive, to the point of being able to distinguish the handwriting written on its surface and withstand 5,000 deformations, recovering in about a quarter of a second.

Dr Shen said, “It is a surprising result for electronic skin to maintain hardness after repeated use, which mimics the elasticity and rapid recovery of human skin.”

The new invention could help make prostheses that are also capable of monitoring biological information including changes in blood pressure.

The information could then be shared and stored in the cloud via Wi-Fi.

Co-author Vincent Tung said: “A remaining obstacle to the widespread use of e-skin lies in the expansion of the high-resolution sensor.

“However, laser-assisted additive manufacturing offers new promise.”

While the first port of call is medical, the e-skin could benefit from a wide range of products, according to Cai, including sensor tape for measuring the structural health of furniture, aircraft and buildings.

“We see a future for this technology beyond biology.”

The results were published in the journal Science Advances.