The last attempt at this -- a watch -- irritated skin. This one uses lower voltage.
"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."
This could bring the price down. When a new diagnostic approach is created and/or new treatments are created, disease categories often shift to make more people have the disease. So it is possible a _whole lot_ more people would be screened for/diagnosed with/treated for T2D once this exists. Open question whether that is a good, bad or indifferent thing. The standard pattern is for the disease category to expand until it has clearly overshot, and then either be debunked, or reduce to a more plausible level.
I would _totally_ buy this thing, if it existed. Because, Data!
(FWIW, I've owned an electronic blood pressure monitor -- I'm on my second -- for over a decade, and I recently added one of those clippy OSAT monitors. Because it was $20 on Amazon. R. held is breath for a while to see how far he could get the number down.)