Sweaty Fingers

Fingerprint in a glass

Dropped your phone again? Don’t sweat it!

This is Sandra Tsing Loh with the Loh Down on Science.

Our fingerprints help us grip slippery smooth surfaces like phones or drinking glasses! But how?

Seoung-Mo Yum at Seoul National University and colleagues started scanning fingerprints. Four participants pressed their finger pads on smooth glass for five minutes. Using high-tech laser-based imaging, the researchers scanned the ridges and tiny sweat ducts in between. They measured friction and hydration levels.

And? Yum found that our sweat glands turn ON to help us grip. Sweat softens the ridges on our fingers and increases friction. But doesn’t that make our fingers MORE slippery? NO! The glands turn OFF just before we get butterfingers. Hurray!

Yum hopes this research could inspire better prosthetic design. Artificial hands with “fingerprints” could help their users grip tools and open phones more easily.

So thank your sweaty fingers while you browse Twitter in bed. Without them, you’d drop your phone on your face even more!

As for that dripping Ben ‘n’ Jerry’s on your blanket — we can’t help you!

Reference: Yum, S. M., Baek, I. K., Hong, D., Kim, J., Jung, K., Kim, S., Eom, K., Jang, J., Kim, S., Sattorov, M., Lee, M., Kim, S., Adams, M.J., Park, G. Fingerprint ridges allow primates to regulate grip. Proceedings of the National Academy of Sciences, 117(50), 31665-31673 (2020). https://doi.org/10.1073/pnas.2001055117