Nanotechnology researchers say a new device could one day let diabetics use tattoos, instead of needles, to check their blood-sugar level.

Scientists at Draper Laboratory, in Cambridge, Mass., have developed a tiny device called a nanosensor that measures blood sugar levels. The nanosensor changes color as the blood-sugar level around it changes.

Heather Clark, an analytical chemist who heads Draper's optical nanosensors project, believes that embedded into the skin as a tattoo, nanosensors could monitor diabetics' blood sugar.

"It changes from yellow to purple, depending on how much glucose is present in the solution around it," she said. "And it also shines very brightly when there's no glucose and gets dimmer as glucose is in its presence."

"(You would) take something like an optical mouse and run it over the skin to see what your glucose levels would be," she added.

The nanosensor tattoo would also provide constant readings, unlike the traditional method, which misses fluctuations in glucose levels between tests, Clark said.

Seven-year-old Cade Poirier is one of the 24 million Americans with diabetes who prick their fingers several times a day.

Cade's mother, Kara Poirier, said she likes that the new method could spare her son some pain.

"That'd be awesome. It would eliminate the need for so many (needles) throughout the day," Poirier said.

Researchers said they plan to test the nanosensors on mice in the coming weeks. They hope nanosensors can be available for diabetics in the next five to 10 years.