Molecular Manufacturing is Here

[mechadense]

Since I'm investigating molecular manufacturing
(or atomically precise manufacturing APM - the newer name)
I think I can clarify a bit how this development brought up here ties in into the big picture of APM.

First some minimal details about what this "molecule making machine" here is actually all about:
http://www.scs.illinois.edu/burke/fi...32_Science.pdf
The the "Suzuki coupling" is used to make carbon carbon bonds
https://en.wikipedia.org/wiki/Suzuki_reaction
like so: ...≡C-B(OH)2 + Br-C≡... - > ...≡C-C≡... + waste
To continue after a first reaction one needs pre-delivered
building block molecules that are at least double capped
like so: Br-C≡...≡C-B(OH)2
But this would self polymerize. That is it would form "infinite" chains.
So the solution found was to temporally cap (chelate) the boron end with a molecule called-
"trivalent N-methyliminodiacetic acid (MIDA fro short)" like so:
http://www.sigmaaldrich.com/chemistr...boronates.html
For purification it was found that the MIDA caps on the growing product molecules can be locked/released to/from silica particles by different solvents.

Limitations of this process that I'm not clear about are:
# How small/big can the pre-delivered building block molecules be?
# The pdf-document says that they can create loops. How? How tight can these loops be? How close can they be together? (I highly doubt big polycyclic diamondoid cages are possible. Not to speak of strained ones.)
# Can this be done hierarchically or only serially? (Hierarchically would extend scalability a bit.)

Limitations that are obviously present:
Since this is conventional chemistry and not mechanosynthesis the yields are low and the error rates are high. Every synthesis step can easily have losses in the single digit percentual range. Thus this is only suitable for small molecules (as the work says itself) and does not scale up very far.

In light of early APM I suspect this could be useful for:
# The synthesis of light activated "motor molecules"
# The synthesis of novel side chains for foldamers (for boosting stiffness & symmetry)
# Maybe short self-assembling strands (like in structural DNA nanotechnology that exclusively uses short oligonucleotide strands)
# ...

With early APM I'm referring to "Coarse-block APM systems" page 33:
https://energy.gov/sites/prod/files/...%20Drexler.pdf
I'm not referring to what is shown in the INFAPM workshop video! That video is (as I see it) just about the "System-level tech demos" dead end in the diagram.

While the "molecule making machine" here certainly is a major step for medicine I'm not sure about in how far this will tie in into the bootstrapping of advanced APM.

I'm writing a website about APM atomically precise manufacturing:
http://apm.bplaced.net

As a side-note: I certainly wouldn't count that molecule making process as a form of "3D printing" just because it's additive manufacturing.
# It handles discrete parts. That is usually called pick and place assembly but ...
# There is also no active positioning involved whatsoever.
It's more like going from painstaking chemistry-research to straightforward chemistry-engineering. But the term "chemical engineering" is already taken.
"Programmable chemistry" maybe ... ?