Nanotechnology httpnano.xerox.comnano by lqh68203

VIEWS: 8 PAGES: 56

									   Nanotechnology
http://nano.xerox.com/nano

     Ralph C. Merkle
      Xerox PARC
     www.merkle.com


                             1
               See
http://nano.xerox.com/nanotech/talks

     for an index of talks


                                   2
Sixth Foresight Conference on
  Molecular Nanotechnology
      November 12-15
      Santa Clara, CA
www.foresight.org/Conferences

                                3
Manufactured products are made
from atoms.
The properties of those products
depend on how those atoms are
arranged.



                                   4
        It matters
 how atoms are arranged

• Coal          • Diamonds
• Sand          • Computer chips
• Dirt, water   • Grass
  and air

                               5
   Today’s manufacturing
methods move atoms in great
 thundering statistical herds

         •   Casting
         •   Grinding
         •   Welding
         •   Sintering
         •   Lithography
                                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://nano.xerox.com/nanotech/feynman.html
                                                     7
Most interesting structures that are at
least substantial local minima on a
potential energy surface can probably be
made one way or another.

      Richard Smalley
      Nobel Laureate in Chemistry, 1996



                                           8
         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
                                                 9
      Terminological caution
The word “nanotechnology” has become very
  popular. It can be used indiscriminately to
  refer to almost any research area where
  some dimension is less than a micron (1,000
  nanometers) in size.

Example: sub-micron lithography


                                                10
Possible arrangements of
         atoms



         What we can make today
              (not to scale)
     .




                                  11
The goal of molecular
  nanotechnology:
   a healthy bite.

   .




                        12
                   Molecular
                  Manufacturing



           We don’t have
           molecular manufacturing
           today.

           We must develop
           fundamentally new
       .   capabilities.



What we can make today
     (not to scale)                  13
“... 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.”
     from The Prince, by Niccolo Machiavelli

                                           14
We’ll start a major project to develop
 nanotechnology when we answer
       “yes” to three questions:

• Is it feasible?
• Is it valuable?
• Can we do things today to speed it’s
  development?


                                         15
                                                   Produc
                                          Products
                     Core molecular              Products
                     manufacturing   Products
                                            Products
                     capabilities   Products Products
                                             Products
                                  Products
                                     Products Products
Today                                  Products Products
                                             Products
                                  Products
                                               Products
                                     Products
   Overview of the                         Products
   development of                                Products
                      Products
   molecular                                Products
                                                    Produc
   nanotechnology                           Products
                                      Products Products
                                                  16
                                              Products
Two more fundamental ideas

• Self replication (for low cost)
• Programmable positional control (to
  make molecular parts go where we
  want them to go)



                                        17
Von Neumann architecture
for a self replicating system

    Universal           Universal
    Computer           Constructor


http://nano.xerox.com/nanotech/vonNeumann.html


                                           18
Drexler’s architecture for an
         assembler

   Molecular            Molecular
   computer            constructor



        Positional device   Tip chemistry




                                            19
  Illustration of an assembler




http://www.foresight.org/UTF/Unbound_LBW/chapt_6.html

                                                 20
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

                                              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://nano.xerox.com/nanotech/selfRep.html
                                               22
Complexity of self replicating systems
                (bits)
C program                                   808
Von Neumann's universal constructor500,000
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

                                                           23
              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)
                                                24
            How strong?
• 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
                                         25
             How long?
• The scientifically correct answer is
  I don’t know
• Trends in computer hardware suggest
  early in the next century — perhaps in
  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
• 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
Bucky tube glued to SPM tip
          (Dai et al.)




         http://cnst.rice.edu/TIPS_rev.htm
                                             32
Building the tools to build the tools

• Direct manufacture of a diamondoid
  assembler using existing techniques
  appears difficult (stronger statements
  have been made).
• We should be able to build intermediate
  systems able to build better systems
  able to build diamondoid assemblers.

                                        33
Diamond Physical Properties
 Property                         Diamond’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




                                                                                 34
A hydrocarbon bearing




http://nano.xerox.com/nanotech/bearingProof.html

                                             35
       A planetary gear




http://nano.xerox.com/nanotech/gearAndCasing.html
                                              36
A proposal for a molecular
     positional device




                             37
           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.
                                            38
 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.

                                                            39
   A hydrogen abstraction tool




http://nano.xerox.com/nanotech/Habs/Habs.html

                                                40
Some other molecular tools




                             41
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

                                          42
The impact of molecular
     manufacturing
depends on what’s being
     manufactured
 •   Computers
 •   Space Exploration
 •   Medicine
 •   Military
 •   Energy, Transportation, etc.

                                    43
          How powerful?
• In the future we’ll pack more computing
  power into a sugar cube than the sum
  total of all the computer power that
  exists in the world today
• We’ll be able to store more than 1021
  bits in the same volume
• Or more than a billion Pentiums
  operating in parallel
                                        44
                   Space
• Launch vehicle structural mass will be
  reduced by about a factor of 50
• Cost per pound for that structural mass
  will be under a dollar
• Which will reduce the cost to low earth
  orbit by a factor of better than 1,000

     http://science.nas.nasa.gov/Groups/Nanotechnol
       ogy/publications/1997/applications/
                                                  45
  It costs less to launch less
• Light weight computers and sensors will
  reduce total payload mass for the same
  functionality
• Recycling of waste will reduce payload
  mass, particularly for long flights and
  permanent facilities (space stations,
  colonies)

                                        46
Disease and illness are
caused largely by damage at
the molecular and cellular
level

Today’s surgical tools are
huge and imprecise in
comparison
                                      47

    http://nano.xerox.com/nanotech/
In the future, we will have fleets
of surgical tools that are
molecular both in size and
precision.

We will also have computers
that are much smaller than a
single cell with which to guide
these tools.                      48
     A revolution in medicine
• Today, loss of cell function results in cellular
  deterioration:
            function must be preserved

• With future cell repair systems, passive
  structures can be repaired. Cell function can
  be restored provided cell structure can be
  inferred:
            structure must be preserved
                                                     49
                                 Cryonics
              37º C                                   37º C




                 Freeze                           Revive
Temperature




                           -196º C (77 Kelvins)

                          Time
                           (~ 50 to 150 years)

                                                           50
               Clinical trials
           to evaluate cryonics
•   Select N subjects
•   Freeze them
•   Wait 100 years
•   See if the medical technology of 2100 can
    indeed revive them

But what do we tell those who don’t expect to
  live long enough to see the results?

                                                51
       Today’s choice:
     would you rather join
The control group
 (no action required)?

Or the experimental group
 (contact Alcor: www.alcor.org)?


                                   52
Military applications of molecular
manufacturing have even greater
potential than nuclear weapons to
radically change the balance of
power.

    Admiral David E. Jeremiah, USN (Ret)
    Former Vice Chairman, Joint Chiefs of
Staff
 http://nano.xerox.com/nanotech/nano4/jeremiahPaper.htm
    November 9, 1995
                                               53
 Nanotechnology and energy
• The sunshine reaching the earth has
  almost 40,000 times more power than
  total world usage.
• Molecular manufacturing will produce
  efficient, rugged solar cells and
  batteries at low cost.
• Power costs will drop dramatically

                                         54
     Nanotechnology and the
          environment
• Manufacturing plants pollute because
  they use crude and imprecise methods.
• Molecular manufacturing is precise — it
  will produce only what it has been
  designed to produce.
• An abundant source of carbon is the
  excess CO2 in the air
                                        55
The best way
   to predict the future
       is to invent it.

          Alan Kay

                           56

								
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