There’s Plenty of Room at the Bottom An Invitation to Enter a New Field of Physics
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Transcript of There’s Plenty of Room at the Bottom An Invitation to Enter a New Field of Physics
There’s Plenty of Room at the BottomAn Invitation to Enter a New Field of Physics
Richard Feynman
1959
2
Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
3
Introduction
In 1959, Feynman observed:
• Nobody studied applied physics of the
very small
• No theoretical knowledge seemed likely to
result.
• Practical applications seemed enormous.
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Introduction …
“Why cannot we write the entire 24 volumes of the Encyclopedia Brittanica on the head of a pin?”– A pin’s diameter = 1/16 inch.– Magnify by 25,000:
• 25,000 / 16 = 130.2 feet.• It’s area = 13,314 square feet• This is enough to fit the Brittanica.• It thus suffices to shrink it to 1/25,000.
– At that scale, 1 half-tone dot = 32*32 atoms.– This is big enough to work.
5
Introduction …
Such a miniaturization is readable.• Make a temporary copy of mold
1. Press the pin’s head into plastic; peel off plastic;
• Construct a copy of mold1. Evaporate silica into the plastic
2. Evaporate gold at an angle (only raised parts coated);
3. Dissolve plastic, leaving only silica & gold.
• Read the copy1. Look thru this “cloth” with an electron microscope.
Original mold (pin) is reusable.
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Gold deposition
1.
2.
Angle of deposition
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Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
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How do we write small?
Use lenses in reverse:
• Pass light thru focusing on a small spot.
• Focused light is intense. Use material that can be etched by this focused energy.
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How do we write small? …
• Entire LOC fits in area of a 35-page magazine.
there is room at the bottom.
• Feynman then demonstrates:
– There is plenty of room at the bottom.
– Using physics known in 1959(!).
10
Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
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Information on a small scale
• Encode information as bits: 1 char = 7 bits.
• Using volumes instead of surfaces– 5 X 5 X 5 = 125 atoms of 1 metal for 1– 125 atoms of another metal for 0– The Brittanica = 1015 bits– All of mankind’s books fit in 1/200 inch cubed.
• (Reading inside the cube is not discussed.)• Nature uses approximately 50 atoms/bit in DNA.
12
Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
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Better electron microscopes
• A 100-fold improvement in electron microscopy goes a long way.
• It is possible:– 1959 microscopes resolve to 10 angstroms.– Wave length of electron is 1/20 angstrom– 100-fold improvement thus is possible.
(been done?)
• Applications to scientific problems:– See DNA, RNA, the cell at work.– See chemical reactions at work.
• Is there a physical way to synthesize chemicals?
14
Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
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The marvelous biological system
• Cells don’t just write information, they are active. – Replicating parts (e.g., proteins)– Replicating themselves (mitosis)– Replicating an entire organism.
• Some cells move; all have moving parts.• Can we make small:
– Computers– Other maneuverable devices?
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Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
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Miniaturizing the computer
• Make wires 10 – 100 atoms in diameter.
(In 1959, computers filled entire rooms.)
• Feynman speculates: 106 bigger computers
could perform qualitatively harder tasks.
– E.g., face recognition, at which the brain excels
(occupies an enormous % of the human brain).
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Miniaturizing the computer …
• Brain’s microscopic elements >> computers.
• What if we made sub-microscopic elements?
• Feynman: faster computers ultimately must
have smaller elements
(Speed of light lower bound on latency)
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Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
20
Miniaturization by evaporation
• Make small elements using evaporation:
– Evaporate:
• a metal layer;
• an insulation layer;
• repeat until have all the elements you want.
• ICs, “invented” much later, (still!) made this
way.
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Miniaturization by evaporation …
• Make small machines (not just computers) using small tools?
• What are the problems?– Resolution of the material.
• A flywheel of diameter 10 atoms won’t be round.
– Weight/inertia do not dominate at smaller scale.– Electrical parts (e.g., magnetic fields) must be
redesigned (but can be done).
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Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
23
Problems of lubrication
• Heat dissipates rapidly at that scale.
• Don’t lubricate!
• Feynman’s friend, Hibbs: nanoscale machines as medical agents, running around inside our bodies.
• How to make small things:– With existing tools, make smaller tools.
– With smaller tools, make yet smaller tools.
– Iterate.
• What about needed increases in precision?
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Problems of lubrication …
• Increasing precision: an example.1. Make smaller flat surfaces.
2. Take 3 such smaller surfaces. Rub them together until they are flat enough at that scale.
• At each level, perform precision-improving actions, at that scale.
• Use simultaneous replication to increase manufacturing efficiency.
25
Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
26
100 tiny hands
• Fractal branching ultra-dexterous robots (Bush robots)H. Moravec, J. Easudes, and F. Dellaert
NASA Advanced Concepts Research Project, December, 1996.
Each level is a hand.The tip of each finger has a Smaller hand.We get an exponential number of small fingers
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100 tiny hands …
• Feynamn notes, at this scale:
– Gravity is almost imperceptible compared to
Van der Waals molecular attraction.
– Van der Waals attractions make things at
this scale attract (stick).
– Designs must take account for these forces.
28
Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
29
Rearranging the atoms
• Constructing materials atom by atom gives
“materials science” enormously more potential.
• E.g., make arrays of tiny circuits that emit light
at the same wavelength in the same direction.
(This is being done now in laboratories.)
• Resistance problems increase at that scale.
Suggests using superconductivity, as 1 approach.
30
Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
31
Atoms in a small world
• Atoms on a small scale satisfy laws of quantum mechanics.– Nothing acts like this at a large scale.– We can exploit:
• quantized energy levels• Interactions of quantized spins, etc.
• Manufacturing perfection:– If resolution is less than 1 atom, then each
copy is exact, atom for atom.
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Atoms in a small world …
• Replace chemistry with physical manufacture.
• Proposed a competition:
Who can build the smallest motor, for example.
33
Outline
• Introduction• How do we write small?• Information on a small scale• Better electron microscopes• The marvelous biological system• Miniaturizing the computer• Miniaturization by evaporation• Problems of lubrication• 100 tiny hands• Rearranging the atoms• Atoms in a small world• Feynman Prizes
34
Feynman Prizes
• Information on the Feynman Prizes:
http://www.foresight.org/FI/fi_spons.html
1998 Feynman Prize in Nanotechnology, Theory
• Ralph Merkle (Xerox PARC)
• Stephen Walch (ELORET at NASA Ames)
For computational model of molecular tools for
atomically-precise chemical reactions.