From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Mon Aug 20 2001 - 12:09:50 MDT
On Mon, 20 Aug 2001, Eugene Leitl wrote:
> I was just restating what Smalley said when he spoke about fat fingers,
> which adds an additional set of constraints on how much
> concerted action in tooltip volume is possible.
I still haven't gotten a copy of the print edition of the SciAm issue
(it doesn't seem to have reached mailboxes or magazine stands here in
Seattle yet). I'm going to be interested in seeing whether Smalley's
article expands on this in a substantive way.
I'm in the middle of rereading Chapters 15-16 of Nanosystems and then
I'll probably go back thru Chapter 8 just to make sure I've got a
good feel for this. I think the answer to this is to just use
larger subcomponents that can be grasped by fingers within the
available volume. Its often the case in biology that one will
transfer a very small group (or atom) from one much larger molecule
to another much larger molecule. I think the flaw in Smalley's thinking
may be that you *must* assemble things atom-by-atom. That may not
be the case -- you can assemble things group-by-group. I suspect
there may be a fraction of the phase space that cannot be assembled
by either strategy. How large that fraction is would be mere speculation
at this point I suspect.
While I've always been pretty optimistic about the assembly of diamondoid,
I've been much less optimistic about the assembly of sapphire --
precisely due to the problem of managing to hold Al and O atoms
in the right places. Now assembling small Al2O3 crystals together --
that seems more feasible to me. But that requires a very careful
exploration of the topic of nano-crystal "welding" -- something that
I've got very little knowledge of.
Robert
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