Artificial, Gold Skin Sensors 'Feel' Touch, Temperature and Humidity

Artificial skin would be a huge boon for patients with prosthetic limbs or those who have damaged their skin in incidents such as fires. Now, scientists have used tiny gold particles and a kind of resin to create a new kind of flexible sensor that could one day be integrated into electronic skin, or e-skin. The findings could pave the way for creating "skin" that can be felt by its user.

Flexible sensors have long interested researchers. But scientists have had problems adapting them for real-world use. To make them practical, these sensors would have to run on low voltage, measure a wide range of pressures and make more than one measurement at a time--including humidity, temperature, pressure and the presence of chemicals. In addition, these sensors would have to be both cheap and easy to make--that's a lot of factors to take into account.

Yet this new sensor may possess all of these components. The chip is created from the use of monolayer-capped nanoparticles that are only five to eight nanometers in diameter. They're made of gold and surrounded by connector molecules called ligands. When these nanoparticles were laid on top of a substrate--in this case, PET (flexible polyethylene terephthalate),--the resulting compound conducted electricity differently, depending on how the substrate was bent.

"Monoplayer-capped nanoparticles can be thought of as flowers, where the center of the flower is the gold or metal nanoparticle and the petals are the monlayer of organic ligands that generally protect it," said Hossam Haick, one of the researchers, in a news release.

So what does this mean exactly? The new sensor could detect a large range of pressures, from tens of milligrams to tens of grams. This means that the sensor could potentially be used to help create artificial skin that can resist and "feel" pressure.

"The sensor is very stable and can be attached to any surface shape while keeping the function stable," said Nir Peled, Head of the Thoracic Cancer Research and Detection Center and Sheba Medical Center who was not involved in the research, in a news release.

The findings could help pave the way for the development of artificial skin. This could mean the difference between an artificial limb that can move like the real thing and an artificial limb that can feel like the real thing.

The findings are published in the journal ACS Applied Materials & Interfaces.