New, affordable sensors that track breathing, heart rate, and ammonia have been incorporated into face masks and t-shirts by Imperial researchers.
Applications could include tracking stress, exercise, and sleep as well as detecting and monitoring disease through breath and vital signs.
The sensors are affordable to make because they are spun from a brand-new cotton-based conductive thread called PECOTEX created by Imperial. PECOTEX is compatible with industry-standard computerized embroidery machines and costs just $0.15/m of thread, which can be used to effortlessly incorporate more than 10 sensors into clothes.
The flexible medium of clothing means our sensors have a wide range of applications. They are also relatively easy to produce which means we could scale up manufacturing and usher in a new generation of wearables in clothing.
Fahad Alshabouna, Study First Author and PhD Candidate, Department of Bioengineering, Imperial College London
The sensors were sewn into a face mask to track respiration, a shirt to track heartbeats, and fabrics to track gases such as ammonia, which could be used to measure liver and kidney function. The ammonia sensors were created to test whether embroidery could also be used to make gas sensors.
Alshabouna added, “We demonstrated applications in monitoring cardiac activity and breathing, and sensing gases. Future potential applications include diagnosing and monitoring disease and treatment, monitoring the body during exercise, sleep, and stress, and use in batteries, heaters, and anti-static clothing.”
Materials Today published the research.
Wearable sensors, such as those found in smartwatches, provide non-invasive continuous monitoring of human health and welfare. Wearable sensors that are smoothly incorporated into clothing are not currently available due to the lack of appropriate conductive threads on the market.
This is where PECOTEX becomes relevant. The material, created and spun into sensors by Imperial researchers, is machine washable, more electrically conductive, and less breakable than commercially available silver-based conductive threads, enabling the addition of additional layers to produce more intricate types of sensors.
Both before and after the sensors were embroidered into garments, the researchers tested them against commercially available silver-based conductive threads.
PECOTEX was more dependable and less likely to break during embroidery, enabling more layers to be stitched on top of one another.
PECOTEX fared better at conducting electricity than the silver-based threads after embroidery since they had lower electrical resistance.
PECOTEX is high-performing, strong, and adaptable to different needs. It is readily scalable, meaning we can produce large volumes inexpensively using both domestic and industrial computerized embroidery machines.
Dr Firat Güder, Study Lead Author, Department of Bioengineering, Imperial College London
Dr Güder added, “Our research opens up exciting possibilities for wearable sensors in everyday clothing. By monitoring breathing, heart rate, and gases, they can already be seamlessly integrated, and might even be able to help diagnose and monitor treatments of disease in the future.”
The embroidered sensors kept the wearability, breathability, and feel on the fabric's skin. They can also be machine washed up to 30 °C.
The researchers will then look for partners for commercialization and investigate other application areas such as energy storage, energy harvesting, and biochemical sensing for individualized therapy.
The Saudi Ministry of Education, Cytiva, Imperial’s Department of Bioengineering, the Bill and Melinda Gates Foundation, the US Army, and the Engineering and Physical Sciences Research Council (EPSRC, a division of the UKRI) provided funding for this study.
Wearable sensors styled into t-shirts and face masks
Video Credit: Imperial College London
Alshabouna, F., et al. (2022). PEDOT: PSS-modified cotton conductive thread for mass manufacturing of textile-based electrical wearable sensors by computerized embroidery. Materials Today. doi:10.1016/j.mattod.2022.07.015.