Wearable body sensors are becoming the latest "must-have" technology. Now scientists from the Tsinghua University in China report they are using silk to develop a more sensitive and flexible generation of these multi-purpose devices that monitor a slew of body functions in real time.
"There is a whole world of possibilities for silk sensors at the moment. Silk is the ideal material for fabricating sensors that are worn on the body," researcher Yingying Zhang, Ph.D., said in a statement.
The researchers are presenting their work this week at the 254th National Meeting & Exposition of the American Chemical Society (ACS).
Body sensors, which are usually made with semiconductors, have shown great potential for monitoring human health. But they have limitations. For instance, strain sensors, which measure changes in force, cannot be highly sensitive and highly stretchable at the same time.
Silk, a natural fibre that is stronger than steel and more flexible than nylon, could overcome these problems, according to a new report by ScienceDaily.
As one of the most coveted fabrics in the world, the material is also lightweight and biocompatible.
"One possibility we foresee is for them to be used as an integrated wireless system that would allow doctors to more easily monitor patients remotely so that they can respond to their medical needs more rapidly than ever before," Zhang said.
However, the fibre doesn't conduct electricity very well. To address this challenge, researchers at Tsinghua University in China sought to find a way to boost the conductivity of silk so it could be successfully used in body-sensing devices.
The researchers decided to try two diverse strategies, according to a news release. In one method, they treated the silk in an inert gas environment with temperatures ranging from 1,112 degrees to 5,432 degrees Fahrenheit. Consequently, the silk became infused with N-doped carbon with some graphitized particles, which is electrically conductive.
Using this method, the researchers have developed strain sensors, pressure sensors and a dual-mode sensor capable of measuring temperature and pressure at the same time.
In the other method, the team fed either carbon nanotubes or graphene to silkworms. Some of these nanoparticles were naturally added into the silk produced by the worms. So far, this method has not produced electrically conductive fibers, but the researchers are still experimenting with this technique and are confident they can make it work.
Based on the preliminary results, researchers are keen on exploring ways to develop an integrated set of silk-based, self-sustaining sensors that would be powered by nano-generators.
The technology could also be used to build more practical robots that can be more sensitive to touch and temperature and can even differentiate between different people's voices, researchers say.
The research's funding is from the National Natural Science Foundation of China and the Key Technologies Basic Research and Development Program.