Researchers at the University of Cambridge have leveraged recent advances in 3D printing to produce electronic fibers that could be used as sensors for health monitoring, all while being invisible to the naked eye. The fibers were demonstrated as portable respiratory sensors, but the team says the approach can be used to produce low-cost sensors for a range of applications.
The team’s 3D printing technique uses silver and semiconducting polymers to produce a conducting fiber core, wrapped in a thin polymer sheath. It is similar in structure to typical electrical wiring in this way, but has a diameter of must a few micrometers, around 100 times thinner than a human hair.
The scientists turned this fiber sensor into a portable respiratory monitor by applying it to a face covering, and then using it to monitor the subject’s breathing. The team used the sensor to not only successfully detect signs of rapid breathing, shortness of breath and simulated coughing, but also track where the subject’s mask was leaking.
Applying this to both fabric and surgical masks, the team found that leakage primarily comes from the front, especially during coughing. When it comes to N95 masks, the researchers found that most leakage came out of the sides. This proved a useful experiment given the importance of face masks in tackling COVID-19, but also in demonstrating the potential of the device, which the team says outperforms comparable commercial sensors.
“Sensors made from small conducting fibers are especially useful for volumetric sensing of fluid and gas in 3D, compared to conventional thin-film techniques, but so far, it has been challenging to print and incorporate them into devices, and to manufacture them at scale,” said Dr. Yan Yan Shery Huang from Cambridge’s Department of Engineering, who led the research.
The team was also able to use its versatile 3D-printing technique to produce biocompatible fibers of a similar size and shape to biological cells. These microscopic devices, the team says, could be used to help “guide” cells into desired patterns. Additionally, these fibers could be attached to smartphones to sense sound through acoustically-driven piezoelectrics, and ultimately, help users gain a better awareness of their surroundings.
“Our fiber sensors are lightweight, cheap, small and easy to use, so they could potentially be turned into home-test devices to allow the general public to perform self-administered tests to get information about their environments,” said Huang.
The research was published in the journal Science Advances.
Source: University of Cambridge
