Ultra-fine 3D-printed fibers monitor mask leakage.

Researchers at the University of Cambridge have used the latest advances in 3D printing to produce electronic fibers that can be used as sensors for health monitoring without being seen by the naked eye. The fiber was originally used as a portable breathing sensor for demonstration, but the team says the method could also be used to produce low-cost sensors for a range of applications.

Ultra-fine 3D-printed fibers monitor mask leakage.

The team’s 3D printing technology uses silver and semiconductor polymers to produce conductive fiber cores wrapped in thin polymer sheaths. This approach is similar to a typical wire structure, but only a few microns in diameter, about 100 times thinner than a human hair.

The scientists turned the fiber sensor into a portable respiratory monitor, applied it to a mask, and then used it to monitor the subjects’ breathing. The team used the sensor not only to successfully detect signs of shortness of breath, shortness of breath and simulated cough, but also to sensitively track the leaking position of the subject’s mask.

After applying it to fabric masks and surgical masks, the team found that the leak came mainly from the front, especially when coughing. When it comes to N95 masks, the researchers found that most of the leaks came from the side. Given the importance of masks in solving COVID-19s, this proved to be a useful experiment and a testament to the potential of the device, which the team says performs better than comparable commercial sensors.

“Sensors made from small conductive fibers are particularly useful for volume sensing of fluids and gases in 3D compared to traditional thin-film technologies, but so far printing and incorporating them into equipment and mass-manufacturing them has been a challenge,” said Dr Yan Yan Shery Huang of the Cambridge Engineering Department, who led the study.

The team was also able to use its versatile 3D printing technology to produce bio-compatible fibers similar in size and shape to biological cells. The team says these microscopic devices can be used to help “guide” cells into the desired mode. In addition, these fibers can be connected to a smartphone to sense sound through acoustically driven ballelectonic technology, ultimately helping users better understand their surroundings.

“Our fiber sensors are lightweight, inexpensive, small and easy to use, so they have the potential to become home testing devices that allow the general public to self-test for environmental information.” Huang said.

The study was published in the journal Science Advances.