A team of scientists at the Technion-Israel Institute of Technology discovered how to make a new kind of flexible sensor using tiny gold particles and a kind of resin that could be integrated into electronic skin and attached to prosthetic limbs, allowing amputees to be able to feel changes in their environments.

According to Hossam Haick, professor in the department of chemical engineering and Russell Barrie Nanotechnology Institute, the research team’s invention “can simultaneously sense touch, humidity and temperature, as real skin can.”

This is different from current kinds of electronic skin — or e-skin— which can only detect touch. The new system “is at least 10 times more sensitive in touch than the currently existing touch-based e-skin system,” he said.

This flexible sensor runs on low voltage, measures a wide range of pressures and makes more than one measurement at a time, including humidity, temperature, pressure and the presence of chemicals. By using monolayer-capped nanoparticles that are only five to eight nanometers in diameter, made of gold and surrounded by connector molecules called ligands, the sensors can be made quickly, easily and cheaply.

When laid on top of a substrate made of flexible polyethylene terephthalate, the resulting compound conducted electricity differently depending on how the substrate was bent, allowing for the sensor to detect a large range of pressures, according to study results. By varying the thickness of the substrate, as well as what it is made of, scientists can modify the sensitivity of the sensor and customize it to perform a variety of different tasks.

For more information:

Segev-Bar M. ACS Appl Mater Interfaces. 2013;5:5531-5541.

Disclosure: The researchers report no relevant financial disclosures.