A device that might one day utilize the chemical indicators in sweat to identify changes in a person’s health has successfully undergone testing by researchers.
A team from The Ohio State University recently presented a wireless, battery-free biochemical sensor that could detect the blood sugar, or glucose, that individuals release from their skin when they exercise. The work was published in the journal Science Advances.
The Ohio State researchers created a “smart necklace” that included a working clasp and pendant and was worn around the participants’ necks to track their blood glucose levels as they exercised.
It operates without a battery by reflecting radio frequency signals from an external reader system using a resonance circuit. Participants cycled for a minimum of 30 minutes, had a 15-minute rest, and then resumed cycling after consuming sugar-sweetened drinks.
According to Jinghua Li, co-author of the work and assistant professor of materials science and engineering at Ohio State, the challenge was whether this novel sensor would detect the rise in sweat glucose levels that should occur after consuming a sweetened beverage.
The sensor did effectively track the glucose levels, according to the data, which implies that it will also be able to detect other significant compounds in sweat.
Sweat actually contains hundreds of biomarkers that can reveal very important information about our health status. The next generation of biosensors will be so highly bio-intuitive and non-invasive that we will be able to detect key information contained in a person’s body fluids.
Jinghua Li, Study Co-Author and Assistant Professor, Material Science and Engineering, Ohio State University
Biomarkers are materials that can reveal a body’s most intimate information: sweat, tears, saliva, and urine are examples of physiological fluids that can include everything from sickness, infection, and even signs of emotional stress.
The researchers think that this sensor could one day be modified as bioimplants and used to detect neurotransmitters and hormones in addition to sweat composition. Li believes that this could help identify ion disorders in cerebrospinal fluid linked to secondary brain injury or even result in a new understanding of how the brain works.
Li also noted that the compact nature of the sensing interface means that this smart necklace just needs a little amount of perspiration for the interface to function.
Although it will be some time before a device resembling the prototype used in this study is made accessible to the general public, Li is already considering how to help those who will need this possibly life-saving technology the most.
The sensors are created out of materials that are very thin rather than the thick and stiff computer chips present in our phones and computers. The product is extremely flexible, thanks to its design, which also safeguards the device’s operation and guarantees that it can safely be placed on a person’s skin.
Li added, “We hope that eventually these sensors can be seamlessly integrated into our personal belonging. Some of us may wear necklaces, some may wear earrings or rings. But we believe these sensors could be placed in something we all wear and that it could help us better track our health.”
Jie Zhou and Zhenqiang Ma from the University of Wisconsin-Madison, as well as Shulin Chen, Tzu-Li Liu, and Yan Dong from Ohio State, were the study co-authors.
The National Center for Advancing Translational Sciences of the National Institutes of Health and the Materials Research Science and Engineering Centers of the National Science Foundation provided funding for the project. Various Ohio State sources provided additional funding.
Liu, T. L., et al. (2022) Battery-free, tuning circuit–inspired wireless sensor systems for detection of multiple biomarkers in bodily fluids. Science Advances. doi:10.1126/sciadv.abo7049.