Sweat-analysing patch monitors athletes‘ health in exercise
Image credit: Northwestern University
A sweat-analysing patch developed by an international research team provides real-time data to athletes about the state of their bodies
The electronic sensor, about 2.5cm in diameter, detects key markers in the sweat such as electrolytes, glucose level or PH. As sweat enters four separate compartments of the sensor, chemical reactions take place, which change the colour of the sensor. The user can take a picture with his or her smartphone to analyse the colour change with a dedicated app. The app then provides advice such as to drink more water or replenish electrolytes.
“Sweat is a rich chemical broth containing a number of important chemical compounds with physiological health information,” said Professor John A Rogers, a stretchable-electronics expert from Northwestern University, the USA, who led the international research team behind the invention.
“By expanding our previously developed 'epidermal' electronics platform to include a complex network of microfluidic channels and storage reservoirs, we now can perform biochemical analysis of this important bio-fluid.”
The team tested the single-use device on a group of 21 cyclists. Nine of the volunteers took part in an indoor cycling session, during which data from the sensor were compared with readings acquired through conventional laboratory-based sweat-analysing techniques. The second group of 12 cyclists took part in a long-distance race across a desert near Tucson, Arizona.
The sensor, attached to the skin of a forearm or back, measured four biomarkers – PH, glucose concentration, chloride and lactate.
“We chose these four biomarkers because they provide a characteristic profile that's relevant for health status determination,” said Rogers. “The device also can determine sweat rate and loss, and it can store samples for subsequent laboratory analysis, if necessary.”
The experimental results matched those obtained by the laboratory methods. The athletes didn’t report any discomfort or irritation using the patch.
“The sweat analysis platform we developed will allow people to monitor their health on the spot without the need for a blood sampling and with integrated electronics that do not require a battery but still enable wireless connection to a smartphone," said Rogers’s collaborator Professor Yonggang Huang.
The researchers hope to use the technology in future to analyse other bodily fluids such as saliva and tears. The sensor can already detect markers of certain diseases including cystic fibrosis and could be possibly used to detect residues of drugs in the sweat of recovering addicts or suspect criminals.