Researchers develop needle-free temporary tattoo for glucose monitoring

University of California, San Diego, researchers are developing a noninvasive glucose monitoring tattoo.--Courtesy of University of California, San Diego

As med tech companies home in on next-generation devices for diabetes, researchers are developing a noninvasive temporary tattoo that can monitor glucose levels through the skin.

Scientists at the University of California, San Diego, are making headway on a flexible, easy-to-wear device that comprises patterned electrodes on temporary tattoo paper. The electrodes deliver a very mild electrical current to the skin for 10 minutes, forcing sodium ions carrying glucose molecules to move toward the tattoo's electrodes. A sensor built into the tattoo then measures the strength of the electrical charge produced by the glucose molecules to read a person's overall glucose levels, researchers said in a statement. The scientists detailed their findings in the Dec. 12 issue of Analytical Chemistry.

To test the device, researchers applied the tattoo to 7 men and women between the ages of 20 and 40 with no history of diabetes. The device was able to detect glucose spikes as well as a traditional finger-stick monitor after meals, and none of the volunteers reported feeling discomfort during the test.

Next up, the UCSD researchers plan to tweak the tattoo to include improved glucose-monitoring functions. The device does not yet provide a numerical readout that patients need to screen glucose levels, and the tattoo's sensor only lasts for a day. But electrical and computer engineering researchers are developing the readout technology, and researchers are trying to find ways to make the tattoo last longer while driving down costs, study author Amay Bandodkar said in a statement.

"Presently, the tattoo sensor can easily survive for a day. These are extremely inexpensive--a few cents--and hence can be replaced without much financial burden to patients," he said.

Eventually, the readout instrument will also have Bluetooth capabilities that send information directly to the patient's doctor in real time or store data in the cloud. The temporary tattoo could also be used to measure other important chemicals or test how well a medication is working.

Meanwhile, companies are forging ahead with the development of needle-free blood glucose monitors. Last year, Google ($GOOG) unveiled plans for a contact lens that monitors glucose levels in tears with a miniaturized sensor and wireless chip. In September, Abbott Laboratories ($ABT) won a CE mark for its Libre Flash device, a system that uses a small sensor attached to the back of the arm to detect glucose levels through a tiny filament, forgoing the need for twice-daily finger-stuck blood glucose measurement.

- here's the Analytical Chemistry abstract
- read the release