Common misconceptions about atomically precise manufacturing

Almost everything buildable?

It is often thought that APM is supposed to be able to produce almost anything (often formulated: all allowed structures permissible by physical law) including e.g. food, wood, plastics and metal parts but this is surely not the case.

Take a look at the "mechanosynthesis" and you will find that the range of materials and strucuctures targeted lies in a very narrow range. The magic lies in the diamondoid metamaterials that emulate properties above the atomic level.

This is not to say it will be impossible for all times to assemble materials lying outside the set of now targeted materials. When the technology will have been around for quite a while [advanced extensions] may be able to do this but this is way beyond the scope of any current day APM attainment project.

No food

Advanced APM is not in any way intended to be a means for food production. Some proteins are a good examples of "anti-diamondoid" materials. Very cold temeratures and highly complex tooltip chemistry would be needed. Information extraction from DNA to an atom configuration is not straightforeward to say the least. Trying to compress atom configuration data hirachically like in diamondoid APM systems would probably lead to strange compression artefacts and would need some kind of very advanced scan of the real thing to be made in advance.

No disassembly

When atoms are placed into a stable diamondoid crystal lattice they form multiple bonds. to get them out again one would need to bind them even stronger to the tooltip. But thats not possible anymore since there are e.g. no single bonds that bind stronger than three carbon-carbon bonds. So once placed in most cases the atom stays stuck until the whole part in which it resides in gets burnt.

Many natural materials are very unordered or have at least crystal defects making it necessary to scan the surface and have a plan for every possible situation which might occur. A very difficult problem way beyond the scope of APM attainment projects.