Molecular Nanotechnology zyvex/nano

1. Molecular Nanotechnologywww.zyvex.com/nano Ralph C. Merkle Principal Fellow, Zyvex www.merkle.com

2. Nick Smith, ChairmanHouse Subcommittee on Basic ResearchJune 22, 1999 In Fiscal Year 1999, the federal government will spend approximately $230 million on nanotechnology research.

3. National Nanotechnology Initiative • Announced by Clinton at Caltech • Interagency (AFOSR, ARO, BMDO, DARPA, DOC, DOE, NASA, NIH, NIST, NSF, ONR, and NRL) • FY 2001: $497 million http://www.whitehouse.gov/WH/New/html/20000121_4.html

4. Academic and Industry • Caltech’s MSC (1999 Feynman Prize), Rice CNST (Smalley), USC Lab for Molecular Robotics, etc • Private nonprofit (Foresight, IMM) • Private for profit (IBM, Zyvex) • And many more….

5. There is a growing sense in the scientific and technical community that we are about to enter a golden new era. Richard Smalley 1996 Nobel Prize, Chemistry http://www.house.gov/science/smalley_062299.htm

6. 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 an attempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are too big. Richard Feynman, 1959 http://www.zyvex.com/nanotech/feynman.html

7. The book that laid out the technical argument for molecular nanotechnology:Nanosystemsby K. Eric Drexler, Wiley 1992

8. Three historical trendsin manufacturing • More flexible • More precise • Less expensive

9. The limit of these trends: nanotechnology • Fabricate most structures consistent with physical law • Get essentially every atom in the right place • Inexpensive (~10-50 cents/kilogram) http://www.zyvex.com/nano

10. Coal Sand Dirt, water and air Diamonds Computer chips Grass It matters how atoms are arranged

11. Today’s manufacturing methods move atoms in statistical herds • Casting • Grinding • Welding • Sintering • Lithography

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

13. The goal: a healthy bite. .

14. Products Products Core molecular manufacturing capabilities Products Products Products Products Products Products Products Products Products Products Products Today Products Products Products Products Products Overview of the development of molecular nanotechnology Products Products Products Products Products Products Products Products

15. Terminological caution “Nanotechnology” has been applied to almost any research where some dimension is less than a micron (1,000 nanometers) in size. Example: sub-micron optical lithography

16. Two morefundamental ideas • Self replication (for low cost) • Positional assembly (so molecular parts go where we want them to go)

17. Von Neumann architecture for a self replicating system Universal Computer Universal Constructor http://www.zyvex.com/nanotech/vonNeumann.html

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

19. Illustration of an assembler http://www.foresight.org/UTF/Unbound_LBW/chapt_6.html

20. Advanced Automation for Space Missions Proceedings of the 1980 NASA/ASEE Summer Study 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. http://www.zyvex.com/nanotech/selfRepNASA.html

21. 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://www.zyvex.com/nanotech/selfRep.html

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

23. Complexity of self replicating systems (bits) • C program 800 • Von Neumann's universal constructor 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://www.zyvex.com/nanotech/selfRep.html

24. How cheap? • Potatoes, lumber, wheat and other agricultural products are examples of products made using a self replicating manufacturing base. Costs of roughly a dollar per pound are common. • Molecular manufacturing will make almost any product for a dollar per pound or less, independent of complexity. (Design costs, licensing costs, etc. not included)

25. How long? • The scientifically correct answer is: I don’t know • Trends in computer hardware suggest the 2010 to 2020 time frame • Of course, how long it takes depends on what we do

26. Developmental pathways • Scanning probe microscopy • Self assembly • Progressively smaller positional assembly • Hybrid approaches

27. Moving molecules with an SPM (Gimzewski et al.) http://www.zurich.ibm.com/News/Molecule/

28. Self assembled DNA octahedron(Seeman) http://seemanlab4.chem.nyu.edu/nano-oct.html

29. DNA on an SPM tip(Lee et al.) http://stm2.nrl.navy.mil/1994scie/1994scie.html

30. Buckytubes(Tough, well defined)

31. Buckytube glued to SPM tip(Dai et al.) http://cnst.rice.edu/TIPS_rev.htm

32. Building the tools to build the tools • Directly manufacturing a diamondoid assembler using existing techniques appears very difficult . • We’ll have to build intermediate systems able to build better systems able to build diamondoid assemblers.

33. If we can make whatever we want what do we want to make?

34. Diamond Physical Properties PropertyDiamond’s valueComments 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

35. Strength of diamond • Diamond has a strength-to-weight ratio over 50 times that of steel or aluminium alloy • Structural (load bearing) mass can be reduced by about this factor • When combined with reduced cost, this will have a major impact on aerospace applications

36. A hydrocarbon bearing http://www.zyvex.com/nanotech/bearingProof.html

37. Neon pump

38. A planetary gear http://www.zyvex.com/nanotech/gearAndCasing.html

39. A proposal for a molecular positional device

40. Classical uncertainty σ: mean positional error k: restoring force kb: Boltzmann’s constant T: temperature

41. 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

42. Born-Oppenheimer approximation • A carbon nucleus is more than 20,000 times as massive as an electron, so it will move much more slowly • Assume the atoms (nuclei) are fixed and unmoving, and then compute the electronic wave function • If the positions of the atoms are given by r1, r2, .... rN then the energy of the system is: E(r1, r2, .... rN) • This is fundamental to molecular mechanics

43. Quantum positional uncertainty in the ground state σ2: positional variance k: restoring force m: mass of particle ħ: Planck’s constant divided by 2π

44. Quantum uncertainty in position • C-C spring constant: k~440 N/m • Typical C-C bond length: 0.154 nm • σ for C in single C-C bond: 0.004 nm • σ for electron (same k): 0.051 nm

45. Molecular mechanics • Nuclei are point masses • Electrons are in the ground state • The energy of the system is fully determined by the nuclear positions • Directly approximate the energy from the nuclear positions, and we don’t even have to compute the electronic structure

46. Example: H2 Energy Internuclear distance

47. Molecular mechanics • Internuclear distance for bonds • Angle (as in H2O) • Torsion (rotation about a bond, C2H6 • Internuclear distance for van der Waals • Spring constants for all of the above • More terms used in many models • Quite accurate in domain of parameterization

48. Molecular tools • Today, we make things at the molecular scale by stirring together molecular parts and cleverly arranging things so they spontaneously go somewhere useful. • In the future, we’ll have molecular “hands” that will let us put molecular parts exactly where we want them, vastly increasing the range of molecular structures that we can build.

49. 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.

50. A hydrogen abstraction tool http://www.zyvex.com/nanotech/Habs/Habs.html