Researchers used tiny 3D-printed fibers to create a sensor capable of precisely measuring moisture leakage from surgical and N95 masks. Photo by Andy Wang/University of Cambridge
Sept. 30 (UPI) -- Researchers have developed a new technique for 3D-printing tiny electronic fibers, 100 times thinner than a human hair, that are capable of sensing human breath.
The transparent conducting fibers, described Wednesday in the journal Science Advances, could be used to create a variety of biomedical devices, including moisture flow sensors and portable respiratory sensors.
Scientists suggest the new composite fibers could be integrated into phones to record, not just breath patterns, but also sound and image data.
While the fibers aren't capable of detecting individual viral particles, researchers suggest that by recording high-resolution moisture leakage data, they could be used to identify weaknesses in face coverings used to slow the spread of coronavirus.
Material engineers used additive manufacturing methods -- 3D printing -- to create a miniaturized core-shell fiber structure similar to the basic structure of an electric wire, with a high-purity conducting material for the inner core and a protective polymer sheath for the outer layer.
The fibers are so thin that they appear invisible to the naked eye -- when used to connect small electrical components, they cause small sensing devices to appear to be floating in midair.
"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," lead researcher Yan Yan Shery Huang, lecturer in bioengineering at Cambridge, said in a news release.
To demonstrate the fibers' potential, Andy Wang, an engineering doctoral student at the University of Cambridge and first author of the new study, used the new technology to measure how much breath moisture leaked through his face covering at different breathing rates and while coughing.
The fiber-based sensor tested by Wang was able to record more precise data than comparable commercial sensors. The new fibers were proved especially good at recognizing and recording shortness of breath.
When researchers used their fibers to measure leakage from the two most commonly deployed masks in healthcare settings, they found that during simulated coughs, surgical masks allowed the most leakage through the front, while tight-fitting N95 masks allowed most leakage through the top and sides.
"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 Huang.