Source: University of California, San Diego

This Tattoo for Diabetics Might Mean the End of Finger Pricking

A team of nanoengineers has developed a temporary tattoo that measures glucose

Diabetics engage in a painful ritual every day, often several times: pricking their fingers with a spring-loaded needle to test the glucose in their blood. But that ritual could soon be put to rest, and replaced by a small patch designed to extract and measure blood-sugar levels. Flexible, easy to apply, and inconspicuous, the next-generation wearable is a promising step toward noninvasive monitoring of diabetes, a disease that affects 29.1 million people in the U.S., according to the Centers for Disease Control [PDF]. 

The invention is the work of a team of nanoengineers at University of California, San Diego, who published their proof of concept in the journal Analytical Chemistry. About the thickness of a piece of tape, the device consists of a small sensor and patterned electrodes screen-printed on temporary tattoo paper. A mild electrical voltage applied to the skin pulls fluid from the skin, and the sensor, which contains the enzyme specific to glucose, measures the sugar concentration. 

16054775919_de1727a097_z
Source: University of California, San Diego

The UCSD scientists tested their concept on seven subjects after they ate large meals. The glucose measurements from the tattoo matched those of a traditional finger-stick monitor.

This isn't the first noninvasive glucose sensor. In 2002, Cygnus introduced an FDA-approved wristband, dubbed the GlucoWatch, that used a similar process as the UCSD device. But the product was plagued by problems: It didn't eliminate finger-pricking altogether—users still had to calibrate the device with a standard test strip—and most people reported skin irritation. Joseph Wang, one of the authors of the study and the chair of the school's Center for Wearable Sensors, says that the tattoo uses a lower current than the GlucoWatch and therefore doesn't cause discomfort.

There's still more work to be done to make the device suitable for continuous use, he says, and his department is also developing an instrument to display the glucose reading to users, as well as send that information to the patient's doctor in real time via Bluetooth. Once the concept is optimized, it could be a much cheaper, more convenient alternative to glucose strips, which average more than a dollar each. And removing such cost and comfort barriers could encourage millions of diabetics to comply with the treatment they need.