I found some sources    https://www.sciencealert.com/there-is-now-an-actual-tattoo-that-can-change-colour-based-on-glucose-levels?utm_source=chatgpt.com

https://www.news-medical.net/news/20190723/New-color-changing-tattoos-can-monitor-glucose-levels-and-other-metabolites-in-real-time.aspx?utm_source=chatgpt.com

Curiously

Couldn't find the source. Could you share it?

science

Scientists develop tattoos that monitor biochemical indicators in real time

> A team of German scientists

Couldn't find the source. Could you share it?

Found this one as I was looking for it: https://stacker.news/items/946806/r/south_korea_ln