The technology "has the potential to become the first needle-free approach - and that includes avoiding completely a finger-stick calibration - to monitor blood sugar levels over the course of a day," Dr. Adelina Ilie from University of Bath, UK told Reuters Health by email.

People with diabetes have to monitor their blood glucose level regularly, and there is currently no way to do that without drawing a drop of blood.

Ilie’s team has developed a device that can measure glucose in the fluid just below the skin, called the "interstitial" fluid.

When tested in two healthy human volunteers, the device provided glucose results that closely matched levels measured in the blood, researchers reported in Nature Nanotechnology.

The researchers stress that the device needs further development before it becomes a wearable, simple, blood-free way to measure blood sugar levels.

Nevertheless, Ilie said, "This finding is important, not only for type 1 diabetics, who absolutely need to monitor their (blood sugar) levels accurately and frequently every day, but also for the very large, and rapidly increasing, numbers of type 2 diabetics for whom a device such as ours would enable them to keep their blood sugar concentration within the ‘normal’ range in a very convenient, completely non-invasive, and user-friendly manner."