Athletes who suffer from diabetes or exercise-related hypoglycemia (low blood sugar) may now have a more comfortable way to monitor their blood sugar levels while working out, thanks to a blood glucose-monitoring patch developed by researchers at the Center for Advanced Sensors and Environmental Systems (CASE) at Binghamton University.
Seokheun Choi, the assistant director of CASE and an assistant professor in the department of electrical and computer engineering, said there are inherent flaws in the traditional glucose-testing methods because of risk of contamination from the skin’s surface. These proteins, Choi said, can interfere with glucose detection and decrease the accuracy of readings.
Traditional methods of blood glucose sensing involve the use of a bulky, battery-powered digital glucose meter and lancet that extracts blood though a finger prick. They also require patients to carry accessories, including lancets, alcohol and a glucose meter. More convenient glucose meters have not reached the mainstream, according to Choi, since the current technology can’t be scaled down.
“Conventional measurements are not suitable for preventing hypoglycemia during exercise,” Choi said. “This is because the underlying process relies on invasive blood sampling, causing the possibility of sample contamination with sweat containing various electrolytes and proteins.”
Current glucose-testing devices employ complex sensing techniques, which means it’s hard to make the technology compact and portable, Choi said. Choi’s solution is a noninvasive, ultra-compact, self-powered glucose-monitoring patch that utilizes sweat rather than blood to detect an athlete’s blood sugar levels.
The patch is integrated into a standard adhesive bandage patch and is paper-based, flexible and disposable. By utilizing capillary action, or the tendency of fluids to spontaneously flow through narrow spaces and between fibers, the patch achieves two functionalities at once. It wicks sweat into a enzymatic fuel cell to generate its own power, and then uses the same sweat sample to detect blood glucose levels. This eliminates the need for an external power source and extraneous sensors.
According to Choi, sweat makes an excellent biofluid for monitoring blood glucose, since blood and sweat are biologically similar in terms of their ability to indicate glucose levels. Choi emphasized that the patch samples glucose continuously rather than periodically, and therefore provides real-time blood glucose information.
“The glucose level in sweat is metabolically related to blood glucose,” Choi said. “The measurement is performed during or immediately after exercise, when there is enough sweat to obtain an adequate sample.”
Maedeh Mohammadifar, a third-year graduate student at BU studying electrical and computer engineering, is the second author associated with this project, and assisted undergraduate researchers in developing the patch. She said the innovative enzymatic fuel cell, which is sensitive to glucose, has been in the works for a while. But in this project, sweat was tested for the first time.
“We immobilized some enzymes on the paper, which are sensitive to glucose and react to the different concentrations of glucose,” Mohammadifar said. “For the first time, we tested sweat as a sample. The main thing [in this project] is that it is a noninvasive method.”
While the science behind this blood glucose patch is complex, the technology is easily scalable, Mohammadifar said. The patch is inexpensive to manufacture due to the paper base, and therefore has the capability of being mass-produced. Additionally, she said, the bio-powered fuel cell, which generates power for the patch, has big implications in other areas of biosensing in which traditional batteries aren’t practical.
Today, this technology is being aimed at athletes due to its unique flexible and lightweight nature. However, the patch may become available to the general public in the future, possibly as a resource for those with hypoglycemia.