The Nanoscience Review by deviramarajan

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									The Nanoscience Review
      By Chris Mann
Overview

    • Scale of Nanoscience
 
    • Uniqueness of
      Nanoscience

    • Applications and Future of
      Nanoscience




                                   Schematic of a multiprobe electron
                                         microscope system
The Scale of Nanoscience

      In factors of 10
      1 meter:              fencing swords
                             
      0.1 meters:           softballs
                             
      0.01 meters:          dimes
                             
      1 millimeter:         diameter of a pinhead
                             
      0.1 millimeters:      human hair
      0.01 millimeters...
The Scale of Nanoscience

                  10 micrometers 
                  (0.01 millimeters)
                   
                  the width of a transistor in
                  Intel's 4004 chip, the first
                  commercial microprocessor,
                  released in 1971.



                                 http://www.4004.com/
The Scale of Nanoscience
1 micrometer:
 
  • Thickness of a
    chloroplast
  • Height of suspension
    for many MEM (micro-
    electromechanical)
    devices
  • Size of transistors in
    1985
The Scale of Nanoscience
100 nanometers:
 
  • Scale of a virus 
  • Smaller than all visible
    wavelengths of light,
    smaller than diffraction
    limit 
  • Size of transistors in 2002
The Scale of Nanoscience


  10 nanometers:
   
    • Size of a nucleosome
    • Scale of many
      nanoparticles
    • Smaller than all
      commercial transistors
The Scale of Nanoscience
1 nanometer:
 
  • Smaller than diameter of
    DNA
  • Diameter of single-wall
    carbon nanotubes
  • Scale of smallest features
    ever written
The Scale of Nanoscience


  1 angstrom:
   
    • Scale of atoms
    • Scale of smallest lateral
      features resolved by any
      form of microscopy
The Scale of Nanoscience
So how big is nanoscience?
 
  • Anywhere from a couple of
    atoms up to a couple of
    microns
What makes "nano" unique?
• Scaling down to the nanoscale changes everything

    • Forces are classical and quantum

    • Different techniques are required to characterize
      samples

    • Nanoscale sciences are inherently multidisciplinary
Color effects
   Change the size of a        Change the size of a
   large object, the color     nanoparticle and everything
   doesn't change              changes




                               CdSe nanoparticles of different
   Rubber balls of different   sizes
   sizes
Multidisciplinary

• Topics that are often
  taught separately, like
  biology and quantum
  mechanics, can mix at the
  nanoscale:
   o eg, some enzymes rely
     on quantum tunneling to
     catalyze reactions
Great, nano is small.  So what??

There are real-world applications for nanoscience everywhere. 
 
        Some case studies:
            Computers
            Bio/Medicine
            Advanced materials
Examples in: Computers

• Modern computers use 65 and 45 nm technology; in fact,
  the entire industry is nano

       New and smaller
       measurement
       devices are possible
       through MEMs and
       NEMs; for instance,
       the 3-axis
       accelerometers in the
       iPod Touch/iPhone
Computers

• As computer components scale down, new physics may
  have to be invoked as top-down approaches begin to fail

• New fields are actively being researched, like spintronics

• Will eventually reach an ultimate limit in lateral scale,
  determined by quantum mechanics
Examples in: Bio/medicine

Quantum dots, or nanoparticles,
can be treated so they target
specific sites in cells
Bio/medicine

• Researchers developing single-DNA strand sequencer by
  using nanopores and nanotechnology

• Cancer research is attempting single-cell targeting

• Lab-on-a-chip research is developing quickly
Examples in: Advanced Materials
   Control of nanostructure
   can improve behavior of
   batteries, solar cells,
   structural materials,
   transmission lines, and so
   on
Materials

• Stronger materials can be made through
  nanocharacterization

• Lower energy electronics can be developed using nano-
  techniques

• Commercial food plastic's oxygen permeability improved by
  using nanoconfinement to cause polymer crystallization
Ethical considerations
What about evil nanorobots!?!?!

Self-replicating parasitic nano-
sized evil "robots" already exist:
they're called viruses.

Modern nanoscience is nowhere
near the capabilities of nature.
 
Primary concerns are with toxicity;
these dangers are actively being
studied
Future of nanoscience
   Many researchers are
    actively studying new
          applications for
      nanofabrication and
    nanocharacterization.
                          
 Who knows what the next
   breakthrough will be?

                              Schematic of a scanning tunneling
                             microscope over a graphene surface

								
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