There is a veritassium YouTube video describing the story of the electron microscope. At some point somebody even proved mathematically that any improvement was a dead end. Then a group of scientists whose research was mostly shunned, and almost at the point of losing their funding, found a way around the limitations and improved the electron microscope to measure atomic level fields, with great impact on science including materials.

PS: veritassium is just amazing. Yesterday I learned that conservation of energy is a local phenomenon and a geometric consequence, not a law of the universe at all. I am 36 with an engineering background and conservation laws were close to sacred laws of the universe. It turns out, not really and it has to do with the universe expanding. Veritassium just drops it like that, with a nice story.