Flexible Skin Patch Tests Sweat and Monitors Your Health

Scientists have developed a flexible, synthetic patch that can be easily attached to the skin to obtain measurements of a person's sweat levels to reveal how the body responds to exercise.

This new device can analyze glucose, Ph, and lactate levels and alerts the user to continue, stop or change the exercise activity. This inexpensive breakthrough innovation is also a crucial step in the future diagnosis of disease, according to researchers from Northwestern University in Illinois.

According to the lead author of the study, John Rogers of Northwestern University's  McCormick School of Engineering and Feinberg School of Medicine, sweat is a rich chemical concentrate that contains important chemical compounds that can reveal a lot about physiological health. Rogers says, simply put, it is like a "lab on the skin."

Scientists aim for people to use this new device to monitor their health in real-time, without the need for blood sampling and laboratory work.

This flexible patch is slim and very lightweight, measuring less than two centimeters. It is considered as an electronic device but does not require any batteries since it can connect wirelessly to a smartphone.

This tiny device works during exercise when sweat beads are absorbed by the microscopic channels of the patch into four compartments. The sweat then reacts with chemical reagents and results in color based readings revealing pH and glucose concentrations, lactate, and chloride.

The patch's wireless electronics sends a signal to a smartphone app to complete the analysis.

During experiments, the team tested the device on two groups of athletes. One group went cycling indoors, and the other one took long distance rides outside. The patches were then attached to the participants' arms and backs.

The results show that indoor cyclists' readings were as reliable as traditional laboratory analyses of the same sweat sample. On outdoor cyclists, the device also proved its durability when it stayed in place and did not leak, revealing quality measurements.

However, these patches are not reusable and can only be utilized for a few hours. Apart from this, the device can also detect a biomarker for cystic fibrosis. It can be adapted for future usage to diagnose disease and monitor the health of those with chronic ailments.

This new study was published in the journal Science Translational Medicine.