Computational molecular nanotechnology

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Computational molecular nanotechnology : 

1 Computational molecular nanotechnology

Remember this URL:http://nano.xerox.com/nano : 

2 Remember this URL:http://nano.xerox.com/nano

The best technical introduction to molecular nanotechnology:Nanosystems by K. Eric Drexler,Wiley 1992 : 

3 The best technical introduction to molecular nanotechnology:Nanosystems by K. Eric Drexler,Wiley 1992

The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not anattempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are toobig. Richard Feynman, 1959 : 

4 The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not anattempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are toobig. Richard Feynman, 1959 http://nano.xerox.com/nanotech/feynman.html

Today’s manufacturing methods move atoms in great thundering statistical herds : 

5 Today’s manufacturing methods move atoms in great thundering statistical herds Casting Grinding Welding Sintering Lithography

Molecular nanotechnology(a.k.a. molecular manufacturing) : 

6 Molecular nanotechnology(a.k.a. molecular manufacturing) Fabricate most structures that are specified with molecular detail and which are consistent with physical law Get essentially every atom in the right place Inexpensive manufacturing costs (~10-50 cents/kilogram) http://nano.xerox.com/nano

Slide 7: 

7 Possible arrangements of atoms . What we can make today (not to scale)

Slide 8: 

8 The goal of molecular nanotechnology: a healthy bite. .

Slide 9: 

9 What we can make today (not to scale) . We don’t have molecular manufacturing today. We must develop fundamentally new capabilities. Molecular Manufacturing

Slide 10: 

10 What we can make today (not to scale) Molecular Manufacturing What we can investigate experimentally .

Slide 11: 

11 What we can make today (not to scale) Molecular Manufacturing . What we can investigate theoretically

Slide 12: 

12 “... the innovator has for enemies all those who have done well under the old conditions, and lukewarm defenders in those who may do well under the new. This coolness arises ... from the incredulity of men, who do not readily believe in new things until they have had a long experience of them.” The Prince, by Niccolo Machiavelli

Slide 13: 

13 Core molecular manufacturing capabilities Today Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Products Overview of the development of molecular nanotechnology

Working backwards from the goal as well as forwards from the start : 

14 Working backwards from the goal as well as forwards from the start Backward chaining (Eric Drexler) Horizon mission methodology (John Anderson) Retrosynthetic analysis (Elias J. Corey) Shortest path and other search algorithms in computer science “Meet in the middle” attacks in cryptography

Two more fundamental ideas : 

15 Two more fundamental ideas Self replication (for low cost) Programmable positional control (to make molecular parts go where we want them to go)

Slide 16: 

16 Von Neumann's universal constructor about 500,000 Internet worm (Robert Morris, Jr., 1988) 500,000 Mycoplasma capricolum 1,600,000 E. Coli 9,278,442 Drexler's assembler 100,000,000 Human 6,400,000,000 NASA Lunar Manufacturing Facility over 100,000,000,000 http://nano.xerox.com/nanotech/selfRep.html Complexity of self replicating systems (bits)

A C program that prints out an exact copy of itself : 

17 A C program that prints out an exact copy of itself main(){char q=34, n=10,*a="main() {char q=34,n=10,*a=%c%s%c; printf(a,q,a,q,n);}%c";printf(a,q,a,q,n);} For more information, see the Recursion Theorem: http://nano.xerox.com/nanotech/selfRep.html

English translation: : 

18 English translation: Print the following statement twice, the second time in quotes: “Print the following statement twice, the second time in quotes:”

Slide 19: 

19 Von Neumann architecture for a self replicating system Universal Computer Universal Constructor

Slide 20: 

20 Drexler’s architecture for an assembler Molecular computer Molecular constructor Positional device Tip chemistry

Slide 21: 

21 The theoretical concept of machine duplication is well developed. There are several alternative strategies by which machine self-replication can be carried out in a practical engineering setting. Advanced Automation for Space Missions Proceedings of the 1980 NASA/ASEE Summer Study http://nano.xerox.com/nanotech/selfRepNASA.html

Diamond Physical Properties : 

22 Diamond Physical Properties Property Diamond’s value Comments Chemical reactivity Extremely low Hardness (kg/mm2) 9000 CBN: 4500 SiC: 4000 Thermal conductivity (W/cm-K) 20 Ag: 4.3 Cu: 4.0 Tensile strength (pascals) 3.5 x 109 (natural) 1011 (theoretical) Compressive strength (pascals) 1011 (natural) 5 x 1011 (theoretical) Band gap (ev) 5.5 Si: 1.1 GaAs: 1.4 Resistivity (W-cm) 1016 (natural) Density (gm/cm3) 3.51 Thermal Expansion Coeff (K-1) 0.8 x 10-6 SiO2: 0.5 x 10-6 Refractive index 2.41 @ 590 nm Glass: 1.4 - 1.8 Coeff. of Friction 0.05 (dry) Teflon: 0.05 Source: Crystallume

A hydrocarbon bearing : 

23 A hydrocarbon bearing

A universal joint : 

24 A universal joint

A planetary gear : 

25 A planetary gear

A differential gear : 

26 A differential gear

Neon pump : 

27 Neon pump

Fine motion controller : 

28 Fine motion controller

A proposal for a molecular positional device : 

29 A proposal for a molecular positional device

Classical uncertainty : 

30 Classical uncertainty σ: RMS positional error k: restoring force kb: Boltzmann’s constant T: temperature

A numerical example of classical uncertainty : 

31 A numerical example of classical uncertainty σ: 0.02 nm (0.2 Å) k: 10 N/m kb: 1.38 x 10-23 J/K T: 300 K

Transverse stiffness of a solid cylinder of radius r and length L : 

32 Transverse stiffness of a solid cylinder of radius r and length L E: Young’s modulus k: transverse stiffness r: radius L: length

Transverse stiffness of a solid cylinder of radius r and length L : 

33 Transverse stiffness of a solid cylinder of radius r and length L E: 1012 N/m2 k: 10 N/m r: 8 nm L: 100 nm

Synthesis of diamond today:diamond CVD : 

34 Synthesis of diamond today:diamond CVD Carbon: methane (ethane, acetylene...) Hydrogen: H2 Add energy, producing CH3, H, etc. Growth of a diamond film. The right chemistry, but little control over the site of reactions or exactly what is synthesized.

Slide 35: 

35 A hydrogen abstraction tool http://nano.xerox.com/nanotech/Habs/Habs.html

Some other molecular tools : 

36 Some other molecular tools

A synthetic strategy for the synthesis of diamondoid structures : 

37 A synthetic strategy for the synthesis of diamondoid structures Positional control (6 degrees of freedom) Highly reactive compounds (radicals, carbenes, etc) Inert environment (vacuum, noble gas) to eliminate side reactions

A modest set of molecular tools should be sufficient to synthesize most stiff hydrocarbons. : 

38 A modest set of molecular tools should be sufficient to synthesize most stiff hydrocarbons. http://nano.xerox.com/nanotech/ hydroCarbonMetabolism.html

The hydrocarbon assembler : 

39 The hydrocarbon assembler Simplifies molecular tools Simplifies reaction pathways Simplifies analysis Simplifies feedstock But a much narrower range of structures (stiff hydrocarbons)

Feedstock : 

40 Feedstock Acetone (solvent) Butadiyne (C4H2, diacetylene: source of carbon and hydrogen) Neon (inert, provides internal pressure) “Vitamin” (transition metal catalyst such as platinum; silicon; tin) http://nano.xerox.com/nanotech/hydroCarbonMetabolism.html

Parts closurefor molecular tools : 

41 Parts closurefor molecular tools A set of synthetic pathways that permits construction of all molecular tools from the feedstock. Can’t “go downhill,” must be able to make a new complete set of molecular tools while preserving the original set. http://nano.xerox.com/nanotech/hydroCarbonMetabolism.html (about two dozen reactions)

We could design and modela simple hydrocarbon assembler today : 

42 We could design and modela simple hydrocarbon assembler today Speed the development of the technology Allow rapid and low cost exploration of design alternatives Provide a clearer target for experimental work Give us a clearer picture of what this technology will be able to do

Critical assumptions in the design of a diamondoid assembler : 

43 Critical assumptions in the design of a diamondoid assembler Must synthesize diamond Highly reactive tools Inert environment Positional control Low error rate (10-12) Rapid unit operations (~10-6 seconds) Simple feedstock

The best way to predict the future is to invent it Alan Kay : 

44 The best way to predict the future is to invent it Alan Kay