Color-changing polymer maps fingerprints
Detecting perspiration pinpoints people’s pores
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2014/04/mr_fingerprint_feat_free.jpg?fit=860%2C460&ssl=1)
SWEAT PRINT Tiny pores on people’s fingertips ooze sweat droplets (shown red in fluorescence image) that can be detected with a new color-changing polymer. The technique could supplement traditional fingerprinting methods, which rely on impressions left by finger ridges.
Courtesy of Kim et al