A small, small, small world

1. A small, small, small world By Ralph C. Merkle Presented by Umangkumar Patel

2. Presentation Overview • Molecular Manufacturing • Utility of Diamond • Basic principles of NanoTechnology • Why Diamond is a Dream Material? • Chemical Vapor Deposition (CVD) • Different types of NanoTechnology • What will we be able to make? • Who’s doing Nanotechnology? • Conclusion

3. Molecular Manufacturing • Manufactured products are made from the atoms. • If we rearrange the atoms in coal (as in a pencil lead) we can make diamond. • If we rearrange the atoms in sand (add a few other elements) we can make computer chips. • If we rearrange the atoms in dirt, water, and air we can make grass.

4. Molecular Manufacturing (Cont.) • Today’s manufacturing methods are very crude at the molecular level. • It’s like trying to make things out of LEGO blocks with gloves on your hand. • Nanotechnology will let us take off the gloves. • We will able to snap together the fundamental building block of nature easily, inexpensively and in an almost arrangement that we desire.

5. Utility of Diamond • Often we want our products to be light and strong. • Depend on the number and strength of the bonds. • Carbon atoms can form four bounds to four neighboring atoms. • Strength to weight ratio of diamond is over 50 times that of steel.

6. Utility of Diamond (Cont.) • We would have to modify the structure to make it tough and shatter proof: perhaps diamond fibers. • Diamond is also wonderful material for making transistors and computer gates. • Computer Gates should switch as quickly as possible: that’s what makes computer so fast.

7. Utility of Diamond (Cont.) • The gates must be made of transistors in which the electrons move as fast as possible over the shortest possible distance. • Today’s computer are made of semiconductors, and the semiconductors of choice is silicon. • Diamond also has greater thermal conductivity, which let’s us move heat out of diamond transistor more quickly to prevent it from getting too hot.

8. Diamond Material properties

9. Basic principles of NanoTechnology • Self Assembly • Position control • Position device • Stiffness

10. Self Assembly • The ability of chemists to synthesize what they want by stirring things together. • Self assembly is a well established and powerful method of synthesizing complex molecular structure. • Basic principal is stickiness • If two molecular parts have a complimentary shapes and charge patterns – one part has a hollow and other part has a bump.

11. Self Assembly (Cont.) • Path to Nanotechnology • It would be hard pressed to make the very wide range of products promised by nanotechnology. • The parts bounce and bump into each other in all kinds of ways. • To make diamond, we need to use indiscriminately sticky parts. • These parts can’t be allowed to randomly bump into each other.

12. Position Control • Basic principal of nanotechnology • At the microscopic scale, the idea that we hold parts in our hands and assemble. • Molecular scale, the idea of holding and positioning molecules is new.

13. Position device • Avoid this problem, we can hold and position the parts. • Molecular parts are both indiscriminately and very sticky. • Positional control at the molecular scale should let us make things. • Molecular bearings can be "run dry", as first suggested by Feynman.

14. Stiffness • Stiffness is a measure of how far something moves when you push on it. • SPM have been made stiff enough to image individual atoms despite thermal noise. • To make something that’s both small and more stiff is challenging.

15. Scanning Probe Microscope

16. Why Diamond is a dream material? • Used as a precious gem, heat sink, abrasive and as wear resistant coating • “Industrial diamond” has been synthesized commercially for over 30 years using HPHT techniques. • Synthesize diamond - Chemical vapor Deposition • Hydrocarbon gas in a excess of hydrogen • CVD Diamond can show mechanical and electronic properties comparable to those of natural diamond.

17. CVD Process • CVD involves a gas-phase chemical reaction occurring above a solid surface, which causes deposition onto that surface. • Involves thermal or plasma activation or use of a combustion flame. • Temperature at 1000-1400 K.

18. Two types of low pressure CVD reactor.

19. CVD Process (Cont.) • Growth rates for the various deposition process vary considerably. • Combustion methods deposit diamond at high rates. • Hot filament and plasma have a much slower growth rates but produce high quality films. • Increasing the growth rates to economically viable rates. • Process is being made using microwave deposition reactors.

20. CVD Diamond film • Diamond initially nucleates as individual microcrystal, which then grow larger until they coalesce into a continuous film. Here, small diamond crystals are seen nucleating on a Ni surface. • Typical appearance of a microcrystalline CVD diamond film grown on Si. The film is polycrystalline, with twinning and many crystal defects apparent.

21. CVD Diamond film (Cont.) • Cross-section through a 6.7 µm-thick diamond film on Si, showing the columnar nature of the growth up from the surface • Nanocrystalline film, exhibiting 'cauliflower' morphology, typical of diamond grown under high (>2%) methane concentrations. • This film is much smoother than the microcrystalline film, but its mechanical and electrical properties are not as extreme.

22. Current Avenues of Molecular Nanotechnology Research • Wet Nanotechnology • Dry Nanotechnology • Computational Nanotechnology

23. Wet Nanotechnology • Biological system that exist primarily in a water environment including genetic material, membranes, enzymes and other cellular components. • Like living organisms whose form, function and evolution are governed by the interactions of nanometer-scale structures.

24. Dry Nanotechnology • Derives from surface science and physical chemistry. • Fabrication of structure in carbon, silicon, inorganic materials, metals and semiconductors. • Electron, magnetic and optical devices.

25. Computational Nanotechnology • The modeling and simulation of complex nanometer – scale structures • The predictive and analytical power of computation • Key players are Drexler and Merkle

26. What will we be able to make? • Improved Transportation • Atom Computers • Military application • Solar energy • Environment

27. Improved Transportation • Today, most airplanes are made from metal despite the fact that diamond has a strength-to-weight ratio over 50 times that of aerospace aluminum. • Lighter materials will make air and space travel more economical.

28. Atom Computers • Computers of the future will use atoms instead of chips for memory. • We’ll have more computing power in the volume of a sugar cube than the sum total of all the computer power that exists in the world today • More than 1021 bits in the same volume

29. Military application • Intelligence gathering devices far too small to be discovered • Computerized biological/chemical weapons • Weapons “smart” enough to kill only the soldiers and not the innocent bystanders. • Active defensive shields.

30. Solar energy • Solar energy replace other resources. • Power storage will become far easier and more reliable.

31. Environment • Most pollution today is a byproduct of manufacturing, transportation, and energy production • MNT is atomically precise, thus zero emissions • Impact = Population x Affluence x Technology • MNT could be used to clean up toxic waste sites by disassembling toxic chemicals into harmless components • MNT could enable a total redesign of our cities, transportation base, energy systems, and relationship to the environment

32. Who’s Doing Nanotechnology?

33. Conclusion • How long before inexpensive solar cells let us use clean solar power instead of oil, coal, and nuclear fuel? • How long before we can explore space at a reasonable cost? • How long it takes depends on what we do and on how fast the technology evolves. • When nanotechnology happens, we will experience explosive change – we need to prepare now.

34. References • http://www.zyvex.com/nanotech/CDAarticle.html • http://www.virtualschool.edu/mon/Bionomics/Nanotechnology.html • http://pchem1.rice.edu/nanoinit.html • http://www.nanozine.com • http://www.zyvex.com/nanotech/talks/ppt • http://www.cphoenix.best.vwh.net/nano-top.html • http://www.bootstrap.org/colloquium/session_03_jacobstein.html • http://www.coatesandjarratt.com/dsmithstp/Nanotechnology • http://www.actionbioscience.org/newfrontiers/merkle.html

35. Questions?