Intermediate and long term objectives in nanotechnology
Overview of the development of molecular nanotechnology
The abstract goal
Two essential concepts
Complexity of self replicating systems
A proposal for a molecular positional device
Drexler's assembler
Something a bit simpler:the hydrocarbon assembler
Major subsystems in a simple assembler floating in solution
The value of a goal:we can work backwards from it(or: it’s hard to build something if you don’t know what it looks like)
The focus today: self replication and molecular tools
A hydrogen abstraction tool
Some other molecular tools
Thermal noise,a classical equation:s2 = kT/ks
Feedstock
A simple binding site for butadiyne
These molecular tools should be able to synthesize a remarkably wide range of stiff hydrocarbons.
Overview
Positioning and initially bonding to a molecule
The first bonds to butadiyne
Creating twohydrogen abstraction tools
Creating two hydrogen abstractions tools
Refreshing ahydrogen abstraction tool
Refreshing a hydrogen abstraction tool
Separating two hydrogen abstraction tools that are bonded together
Radicals weaker than the hydrogen abstraction tool can be created by abstracting a hydrogen from the appropriate precursor
We can dispose of excess hydrogen by making hydrogen rich structures
Extending ahydrogen abstraction tool
Extending a hydrogen abstraction tool
Transferring a dimer from a polyyne to a cumulene(the kind of reaction needed to refresh the carbene tool)
Transferring a dimer from a polyyne to a cumulene
Parts closure
The design and modeling of a simple assembler could be done with existing capabilities.This would:
Email: merkle@xerox.com
Home Page: www.ralphmerkle.com
The PowerPoint '97 version is available.