New Wearable Sensor Accurately Tracks Tiny Changes in the Breath Process

Manchester scientists have developed a new type of wearable sensor that can precisely track your breath, even the slightest changes in the exhaling and inhaling processes. This innovation, described in a recent study published in Advanced Materials, paves the way for improved monitoring of respiratory health and disease.

The sensor, based on a 2D material called hexagonal boron nitride (h-BN), is significantly more sensitive and accurate than previous designs. It can detect even subtle variations in breath patterns, such as those caused by asthma or sleep apnoea.

"Our sensor is like a highly accurate microphone for your breath," says lead author Prof. Cinzia Casiraghi, a researcher at The University of Manchester. "It can pick up on the tiniest changes in airflow, providing valuable physiological information on an individual, for example related to their cardiac, neurological and pulmonary conditions as well as certain types of illness. "

How it works

The active material in the sensor is made of a hexagonal boron nitride ink, which has been designed by supramolecular chemistry to provide enhanced sensibility to water molecules. The ink is deposited between electrodes in the form of a thin film and then an alternating electric field is applied to the electrodes. When you inhale and exhale, the electrical signal of the film changes based on the local humidity, showing a characteristic “V shape” associated to the full breathing cycle. Changes in the V shape can therefore be attributed to changes in the exhaling-inhaling process, for example due to coughing, fever, runny and stuffy nose.

The new sensor has several advantages over existing technologies. It is more sensitive, meaning it can detect smaller changes in breath. It is also faster, with a response time of just milliseconds. And it is not affected by temperature or other environmental factors, making it more reliable for real-world use. Furthermore, it can be easily integrated onto face masks.

Potential applications

The researchers believe that their sensor has the potential to revolutionise the way we monitor respiratory health, and it could be used to track the effectiveness of respiratory treatments.

"This sensor has the potential to make a real difference in the lives of people with respiratory problems," says Dr. Liming Chen, Postdoc in Casiraghi group who has worked on this project. "It could help us to diagnose diseases earlier, track the progression of diseases, and help making personalised treatment plans."

The researchers are now working on extending the technology to achieve high sensitivity and selectivity towards selected biomarkers found in the breath that are associated to diseases, for example respiratory ammonia.

They hope to see their technology in the hands of patients and healthcare providers in the near future.

The National Graphene Institute (NGI) is a world-leading graphene and 2D material centre, focussed on fundamental research. Based at The University of Manchester, where graphene was first isolated in 2004 by Professors Sir Andre Geim and Sir Kostya Novoselov, it is home to leaders in their field – a community of research specialists delivering transformative discovery. This expertise is matched by £13m leading-edge facilities, such as the largest class 5 and 6 cleanrooms in global academia, which gives the NGI the capabilities to advance underpinning industrial applications in key areas including: composites, functional membranes, energy, membranes for green hydrogen, ultra-high vacuum 2D materials, nanomedicine, 2D based printed electronics, and characterisation.