Biosensor Tattoo Monitors Sweat For Health Indicators
San Diego, Calif., April 18, 2013 -- By integrating complex electrochemical sensors with simple, fairground tattoos, nanoengineers have created a highly sensitive, wearable biosensor that monitors the pH and lactate content in sweat. By augmenting conventional sensors that measure vital signs with the added dimensions of chemical information from sweat, the temporary transfer tattoo biosensors can yield a much more comprehensive assessment of the metabolic health of the wearer.
Grad student Amay Bandodkar said the temporary electrochemical tattoo relies on a carbon fiber backbone so that it bends with the skin during normal activity without loss of functionality, and a conductive polymer that is sensitive to pH-levels in sweat. Bandodkar is presenting the team’s research, from the laboratory of Nanoengineering Professor Joseph Wang, at Research Expo at the UC San Diego Jacobs School of Engineering.
“This technology is useful for people who need to monitor their weight and daily levels of physical activity,” said Bandokar. “The higher the quantity of these chemicals in the sweat the higher that person’s physical activity. By keeping a record of these chemicals we can see whether the patient’s stamina is improving.”
The research team is also close to demonstrating a tattoo sensor for detecting sodium and ammonia in sweat. Doctors could also use the device to monitor a patient’s physical activity because the quantities of lactate, sodium and ammonia in sweat are proportional to physical activity.
|The biosensor tattoo is easily disguisable whether applied directly to the skin or sewn into clothing. UC San Diego Jacobs School of Engineering.|
The solution is inexpensive, non-invasive and easily disguisable whether applied directly to the skin or sewn discretely into clothing. It also has applications for the military and security operations in explosives detection. Wang’s Laboratory for Nanobioelectronics’ innovations in printed nanotechnology combined with high-fidelity electrochemical detection have resulted in a device that is fast, highly sensitive, and able to detect targeted chemical compounds while tuning out others that could interfere with its measurements. The researchers have been putting the technology through a series of durability tests, including hand-washing with soap, applying various forms of mechanical strain, and investigating their response over extended durations of wear, including during exercise. That’s because the device must maintain its sensing capability through the rigors of normal wear and tear.