As someone known here for poking ridicule at extreme nanotek claims, let me criticize this criticism. H's principle applies to subatomic particles like electrons which exhibit wave particle duality. An atom as a whole can be manipulated and even imaged, and they have been repeatedly.

However, there are other miniscule atomic level forces, especially frictional, electrostatic, whatever, that arise at these small scales that are making nanoengineering in practice increadibly more difficult than high priest Drexler proported.

The biggest Hoo-ha in Drexler's nanotek vision is the vaunted "assembler", a nanoscale intelligent nanobot, self-powered, 3 dimensionally sensored and 3-D motile, performing purposeful nano engineering tasks. We can't even IMAGINE how to build one of these in a full scale macro world never mind building one at nanoscale.