Fig. 6: a Sweat specimens for non-invasive glucose detection were collected from the forehead, breast and back of five volunteer students before, during and after cycling exercise.

The CAs of the sweat specimens from the forehead (b), breast (c), and back (d) were observed to increase slightly with each successive collection time from before to after cycling. The volume of the test droplet was 2 µL. Error bars indicate the standard deviation of three replicates