The Nanoscience Review by deviramarajan


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									The Nanoscience Review
      By Chris Mann

    • Scale of Nanoscience
    • Uniqueness of

    • Applications and Future of

                                   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.

The Scale of Nanoscience
1 micrometer:
  • Thickness of a
  • Height of suspension
    for many MEM (micro-
  • Size of transistors in
The Scale of Nanoscience
100 nanometers:
  • Scale of a virus 
  • Smaller than all visible
    wavelengths of light,
    smaller than diffraction
  • Size of transistors in 2002
The Scale of Nanoscience

  10 nanometers:
    • Size of a nucleosome
    • Scale of many
    • Smaller than all
      commercial transistors
The Scale of Nanoscience
1 nanometer:
  • Smaller than diameter of
  • 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
What makes "nano" unique?
• Scaling down to the nanoscale changes everything

    • Forces are classical and quantum

    • Different techniques are required to characterize

    • 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

• Topics that are often
  taught separately, like
  biology and quantum
  mechanics, can mix at the
   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
       devices are possible
       through MEMs and
       NEMs; for instance,
       the 3-axis
       accelerometers in the
       iPod Touch/iPhone

• 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

• 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

• Stronger materials can be made through

• Lower energy electronics can be developed using nano-

• 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
Future of nanoscience
   Many researchers are
    actively studying new
          applications for
      nanofabrication and
 Who knows what the next
   breakthrough will be?

                              Schematic of a scanning tunneling
                             microscope over a graphene surface

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