The origin of the the term “nano” comes from the
Greek word “nanos” for dwarf, but in scientific
usage, “nano” means one billionth.
One nanometer is 1/1000000000 of a meter.
Nano science is the study of fundamental
principles of molecules and structures with at least
one dimension roughly between 1 and 100
what exactly is nanotechnology?
Most definitions revolve around the study and control of phenomena and
materials at length scales below 100 nm and quite often they make a comparison
with a human hair, which is about 80,000 nm wide.
It seems that a size limitation of nanotechnology to the 1-100 nm range, the area
where size-dependant quantum effects come to bear, would exclude numerous
materials and devices, especially in the pharmaceutical area, and some experts
caution against a rigid definition based on a sub-100 nm size.
Another important criteria for the definition is the requirement that the nanostructure is man-made. Otherwise you would have to include every naturally
formed biomolecule and material particle, in effect redefining much of chemistry
and molecular biology as 'nanotechnology.'
So nanotechnology can be defined as “The
design, characterization, production, and application of structures, devices, and
systems by controlled manipulation of size and shape at the nanometer scale
(atomic, molecular, and macromolecular scale) that produces
structures, devices, and systems with at least one novel/superior characteristic or
Nanotechnology is the
manipulation of matter at
the nanometer scale to
structures, devices and
2000 Years Ago – Sulfide nanocrystals used by
Greeks and Romans to dye hair.
1000 Years Ago (Middle Ages) – Gold nanoparticles
of different sizes used to produce different colors in
stained glass windows.
1974 – “Nanotechnology” - Taniguchi uses the term
nanotechnology for the first time.
1981 – IBM develops Scanning Tunneling
1991 – Carbon nanotube discovered by S. Iijima
Stinger: Targeted Drug
Nanomaterials is a field which takes a materials
science-based approach to nanotechnology. It studies
materials with morphological features on
the nanoscale, and especially those which have
special properties stemming from their nanoscale
Sunscreens and Cosmetics.
Phosphors for High-Definition TV
Elimination of Pollutants.
University of Granada (Georgia Tech Photo:
In top down technique, generally a bulk material
is taken and machined it to modify into desired
shape and product.
On the other hand, bottom up technique is used
to build something from the basic material.
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