Two things to emphasize (Score 1)

I attended a talk about this work about three weeks ago at the Optical Society of America's topical meeting on Information Photonics in Charlotte. There are two things about this work that I wanted to emphasize. First, this wasn't done using a nail on a person. Rather, a piece of nail that had been trimmed off and subsequently polished before being written was used. They hadn't demonstrated this with a growing nail attached to a living person. Second, they were able to write three different layers at different depths in the nail, which I thought was very cool. Anyway, it was very interesting work.