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Nanostiinta si nanotehnologie
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Intro/history of nanoscience/tech
History and Future of Nanoscience / nanotechnology
Some history: Feynmans prophesy:
Theres plenty of room at the bottom What is nanoscience/nanotechnology? Nano-fabrication Nano tools Materials of nanoscience
Current applications of nano Future applications (dreams)
Intro/history of nanoscience/tech
Feynmans Challenge (~1960)
Why cant we write the Encyclopedia Brittanica on the head of a pin?
Or the entire contents of the library of congress in the volume of a sugar cube?
There is plenty of room at the bottom.
Intro/history of nanoscience/tech
Scales of lengthImportance of size and scale
1 m human being
Sun
10 m
1,000,000,000 m
0.001 m = milli
0.000000001 m = nano
0.000001 m = micro
1,000,000 m Earth
building
thickness of a dime
bacteria
atom
=109
=101
=106
=10-9
=10-6
=10-3
nanoscale
Intro/history of nanoscience/tech
Nano is the scale of atoms and moleculesup to ...
The nanoscale ranges from individual atoms to bacteria.
1 nanometer = 10 atoms
1000 nanometers = 1 bacterium
Intro/history of nanoscience/tech
The push to make things smaller
Intro/history of nanoscience/tech
The power of miniaturization
Intro/history of nanoscience/tech
Moores law
Intro/history of nanoscience/tech
Top down fabrication (integrated circuits)
Use a microscope (light or electron) to write a pattern in a light sensitive layer.
Intro/history of nanoscience/tech
Use an electron microscope beam to make very small patterns
Intro/history of nanoscience/tech
Fabrication of semiconductor crystals -one atomic layer at a time
Produces atomically flat and perfect crystals - layer by layer Can be used for semiconductors or metals Molecular beam epitaxy - developed since ~1975
Intro/history of nanoscience/tech
Fabrication of truly new materials
Molecular beam epitaxy is used to make new types of materials semiconductor devices (transistors,
computer circuits) lasers on a chip (fiber optics, optical
communications) very small and very sensitive read heads
for computer hard disks (laptops, ipods)
Intro/history of nanoscience/tech
Rotary motor
Uses electrostatic force
Intro/history of nanoscience/tech
A nano-mechanical oscillator
Fabrication
Intro/history of nanoscience/tech
Intro/history of nanoscience/tech
Nano-gravimiters
Intro/history of nanoscience/tech
Fabrication from the bottom up
Nano is the scale of atoms -- need tools for visualizing and manipulating individual atoms.
Scanning probe microscopes (~1980s) Move a very small probe over a surface and
study the probe/surface interaction. Different types: Scanning tunneling microscope (STM) Atomic force microscope (AFM) Magnetic force microscope (MFM) + more
Intro/history of nanoscience/tech
Scanning tunneling microscope (STM)
use tunneling currentfrom tip to sample
tunneling ~exp(-x) sohave very high xresolution (
Intro/history of nanoscience/tech
Building - atom by atom
moving and placing Fe atoms on a Cu surface
Intro/history of nanoscience/tech
Building with atoms
abacus with atoms quantum corral
Intro/history of nanoscience/tech
Atomic force microscope (AFM)
move cantilever with atomically sharp tip over a surface or molecule
monitor deflection of cantilever (= spring with k=0.1 N/m -- like a slinky)
cantilever = 0.1 mm long can detect 10-11N and
Intro/history of nanoscience/tech
Atomic force microscope tips
3000 nm
tips are only 10-100 atoms wide
Intro/history of nanoscience/tech
AFM image of graphite surface
Individual atoms on a carbon surface.
Intro/history of nanoscience/tech
DNA on a mica surface
Intro/history of nanoscience/tech
Molecular Electronics
Use scanning probe microscopy to attach leads to individual molecules, and study electrical conduction.
Intro/history of nanoscience/tech
Fabrication of a molecular switch
Conduction through a ROTAXANE molecule changes by a factor of 1000 when the active group is chemically oxidized. In a circuit the switch can be closed by application of a voltage.
Intro/history of nanoscience/tech
New materials: carbon buckyballs and carbon nanotubes
Discovery of buckyballs (fullerenes) C60 and larger.
Can be used to pattern or trap at the nano-scale
Intro/history of nanoscience/tech
Carbon nanotubes
Graphene sheets rolled into cylinders. As small as a few nm in diameter.
Very strong (space elevator?). Can conduct electricity. Use as small pipes, channels, or gears.
Intro/history of nanoscience/tech
Fabrication by self assembly
Use natural properties of atoms and molecules to form nano-scale structures. Molecular beam epitaxy Carbon nanotubes DNA
Use as templates or in other ways.
Intro/history of nanoscience/tech
Current applications of nanoscience
Very powerful computers, mp3 players, ipods Computer hard disks CDs and DVDs Nanostructured materials: ultra-strong and
ultra-light, used in tennis rackets, skiis, cars and airplanes
Intro/history of nanoscience/tech
Nature is a nanoscientist
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Nature uses nanoscalemolecular motors
Intro/history of nanoscience/tech
Molecular motors walk from place to place within a cell
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goal: make nanoscale motors following Natures design
Intro/history of nanoscience/tech
Grand nanoscience challenges for the future
Putting the entire contents of the Library of Congress in a device the size of a sugar cube
Developing materials that are 10 times stronger than steel
Improving the speed and reducing the size of computers
Detecting cancerous tumors that are only a few cells in size (new sensor technologies)
Removing the finest contaminants from water and air
Making motors as small and efficient as biological motors (nano electro-mechanical systems)
Doubling the energy efficiency of solar cells
Intro/history of nanoscience/tech
Nano threads
Tools scanning probe microscopy
Fabrication: top down vs bottom up self assembly
Materials silicon integrated circuits DNA carbon nanotubes and buckyballs
History and Future of Nanoscience / nanotechnologyFeynmans Challenge (~1960)Scales of lengthImportance of size and scaleNano is the scale of atoms and molecules up to ...The push to make things smallerThe power of miniaturizationMoores lawTop down fabrication (integrated circuits)Fabrication of semiconductor crystals -one atomic layer at a timeFabrication of truly new materialsRotary motorA nano-mechanical oscillatorNano-gravimitersFabrication from the bottom upScanning tunneling microscope (STM)Building - atom by atomBuilding with atomsAtomic force microscope (AFM)Atomic force microscope tipsAFM image of graphite surfaceDNA on a mica surfaceMolecular ElectronicsFabrication of a molecular switchNew materials: carbon buckyballs and carbon nanotubesCarbon nanotubesFabrication by self assemblyCurrent applications of nanoscienceNature is a nanoscientistMolecular motors walk from place to place within a cellGrand nanoscience challenges for the futureNano threads