The nano ink particles are tiny, squishy spheres about 120 nanometers across. Inside the sphere are three parts: the glucose detecting molecule, a color-changing dye, and another molecule that mimics glucose.
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If the molecules mostly latch onto glucose, the ink appears yellow. If glucose levels are low, the molecule latches onto the glucose mimic, turning the ink purple. A healthy level of glucose has a "funny orangey," color, according to Clark. The sampling process repeats itself every few milliseconds.
From the Upcoming ueue, submitted by tempeh.