Comment by trelane

Fascinating! Only tangentially related: I've definitely heard of PMMA, and didn't realize it was plexiglass! It's used regularly in semiconductor fabrication. https://kayakuam.com/product/structsure/pmma-positive-resist...

(also waaaay down on the list of uses at https://en.wikipedia.org/wiki/Poly(methyl_methacrylate) but I thought that first link was clearer. Look for "In semiconductor research and industry, PMMA aids as a resist in the electron beam lithography process.")