[KK7NIL]

> we have very little to show in a way of progress. What happened?

Our semiconductors have had features below 100 nm for a while (actual features, not just process node names), so that's been wildly successful.

Why nanofabrication hasn't been as commercially successful outside of semiconductors is a much harder question to answer.

[abraxas]

Yes, of course the etching on silicon process has been refined to a level nobody thought possible. But this is more like a CNC process at a tiny level. What we don't have is additive manufacturing at nano scale. The nano assembler that Drexler and Feynman thought were possible is not panning out.

[KK7NIL]

I'll have to look up that idea of the "nano assembler" that you're referring, but I'll just mention that there is significant additive manufacturing in a modern semiconductor GAAFET node, with the entire transistor being grown.

This video is a good summary of the main steps involved: https://youtu.be/xaKyDrWfHes

It's certainly not as powerful or universal as 3D printing and it might not even be "additive manufacturing" proper, but it is a lot more than just etching/subtractive manufacturing.