Introduction Of Nanotechnology
Junior Research Fellow.
“The branch of technology that deals with dimensions of less than
100 nanometres, especially the manipulation of individual atoms and
"Nano-technology” mainly consists of the processing of separation,
consolidation, and deformation of materials by one atom or one
By Norio Taniguchi
History Of Nanotechnology
The first ever concept was presented in 1959 by the famous
professor of Dr. Richard Feynman in the lecture of
“There’s plenty of rooms at the bottom”
and The Nobel prize was awarded in 1965.
Dr. Richard Feynman
The term “Nano technology” had been coined
by Norio Taniguchi in
Gives the idea of “Molecular Machinery
Manufacturing and Computation”
Prof. Norio Taniguchi
Dr. Eric Drexler
Some Ancient Nano Material
1000 year’s ago different size “Gold Nanoparticles”
are used for produces stained glass windows.
2000 year’s ago “Sulphide Nano crystals” used by the
Greek and Roman for dye of the hair.
Lycurgus Cup(Roman 4th Century)
The glass contains gold-silver alloyed nanoparticles,
which are distributed in such a way to make
the glass look green in reflected light but,
when light passes through the cup, it reveals a brilliant red.
Nature And Nanotechnology
The colours of beetle and butterfly wings come from the scattering of light.
Light hits the nanostructures on their scales.
These nanostructures are typically smaller
than the wavelengths of visible light (smaller than 400 nanometres).
As sticky as a …Gecko?
“On the sole of a gecko’s toes
there are some one billion tiny adhesive hairs,
about 200 nanometres in both width and length.
The shape of the fibres is also significant;
for example, spatula-shaped ends
on the hairs provide particularly strong adhesion.”
Colour Can Be Iridescent, Too!
Thin films are made of nanoparticles,
smaller than 400 nanometers, that
produce iridescent (rainbow-like) colors
when light strikes them.
Iridescent colors change when you look at
the object from different angles.
Approach Of Nanotechnology
Top Down Method Bottom Up Method
Top Down Method
Some of the following method of top down method :
Photolithography : Photolithography uses light (UV,
deep-UV, extreme-UV or X-ray) to expose a layer of
radiation-sensitive through mask polymer(photoresist)
Photolithography : Photolithography uses light to
expose a layer of
through mask polymer(photoresist)
Scanning lithography :
Energetic particles such as electrons and ions can be used to
pattern appropriate resist films leading to features with nanometre
resolution. recently established technology uses nanometre scanning
probes for patterning resist
films and is therefore referred to as Scanning Probe Lithography
E-beam lithography :
Electron beam lithography or Electron-Beam Direct-Write
Lithography scans a focused beam of electrons on a surface
covered with an electron-sensitive film or resist to draw
custom shapes. By changing the solubility of the resist and
subsequent selective removal of material by immersion in a
solvent, sub-10 nm resolutions have been achieved.
Bottom Up method
some of the following method for preparation of nanoparticle.
Chemical vapour deposition :
Precursor gases are delivered into the reaction chamber at approximately
ambient temperatures. As they pass over or come into contact with a
heated substrate, they react or decompose forming a solid phase which and
are deposited onto the substrate. The substrate temperature is critical and
can influence what reactions will take place.
Why Bottom Up
• Allows smaller geometries than photolithography.
• Certain structures such as Carbon Nanotubes and Si
nanowires are grown through a bottom-up process.
• New technologies such as organic semiconductors
employ bottom-up processes to pattern them.
• Can make formation of films and structures much
• Is more economical than top-down in that it does
not waste material to etching
Surface Area to Volume Ratio
In nanomaterial the surface /boundary / interface plays
As surface area per mass of material increase greater amount of
the material can comes contact with surrounding material thus
affect the reactivity.
Classification Of Nanomaterial
Zero Dimensional :
These nanoparticles are spherical in size and the diameter of
these particles will be in the1-50 nm range.
One Dimensional :
These materials are long (several micrometre in length)
but with diameter of only a few nanometre.
Gold Nano particle
Two Dimensional :
These include different kind of Nano films
such as coatings and thin-film-multilayers,
Nano sheets or Nano-walls.
The area of the Nano films can be
large (several square micrometre),
but the thickness is always in Nano scale range
Three Dimensional :
These include bulk materials composed of
the individual blocks which are in
the nanometre scale (1-100 nm).
Solar thin film
Carbon Based Nanotubes
Types Of Carbon Nanotubes :
Single Walled Nanotube (SWNT) :
Multi Walled Nanotube(MWNT) :
Properties Of Nanotubes
Tensile & Compressive Strength :
The tensile strength of” carbon nanotubes is
approximately 100 times greater than
that of steel of the same diameter”.
SWNT nanotube hardness about 25× 109 Pa.
It is higher than Diamond and Prepared under high pressure and
Nanotube is super hard phase and they have bulk modulus of
465-546 GPa (1GPa=10 9)
Spinning Nanotube fibre
Electrical Properties : metallic nanotubes can carry
an electric current
density of 4 × 109 A/cm2,
which is more than 1,000 times greater
than those of metals such as copper,
where for copper interconnects
current densities are limited by electro migration.
It is act as Superconductivity up to 12 K.
Thermal Properties :
SWNT has thermal conductivity 3500 W/ m.K
while Copper has 385 W/m.
Thermal stability in vacuum up to 3100 K and 1000 K in air.
Application Of Nanotechnology
Energy Source :
Microbial Fuel Cell :
cell is a device in which bacteria
consume water-soluble waste such as
sugar, starch and alcohols and
produces electricity plus clean water.
C12H22O11 + 13H2O ---> 12CO2 + 48H+ + 48e-
4H+ + O2 + 4e- 2H2O
Carbon nanotubes - Microbial fuel
Hydrogen Fuel cell :
A fuel cell is a device that converts the chemical energy from a fuel into
electricity through a chemical reaction of positively charged hydrogen ions with
oxygen or another oxidizing agent.
Hydrogen fuel cells power the shuttle's electrical systems, producing a clean by-
product - pure water, which the crew drinks. A fuel cell combines hydrogen and
oxygen to produce electricity, heat, and water.
Health Sector :
Nano Robotics :
He first useful applications of
Nano machines may be in Nano medicine.
For example, biological machines could be used
to identify and destroy cancer cells.
Another potential application is the detection
of toxic chemicals, and the measurement
of their concentrations, in the environment
Nano Sponges :
The development of new colloidal carrier called
Nano sponges has the potential to
solve these problems. Nanosponage is a novel and
emerging technology it can precisely control the
release rates of controlled drug delivery for topical use.
ADVANTAGES OF NANOSPONGES
Targeted site specific drug delivery.
This Technology offers entrapment of wide variety
of ingredients and reduced side effects.
Improved Stability, increased elegance and enhanced formulation flexibility.
Bullet Proof Clothing :
"When a bullet strikes body armour, the fibres of these materials absorb and disperse
the impact energy to successive layers to prevent the bullet from penetrating"
a) Initial model, (b) a deformed
nanotube at its maximum energy
Electro chromic Camouflage :
Scientists are manipulating light so soldiers seem to disappear.
Scientists are also working on
"electro chromic camouflage" – fabric which changes
colours instantly to blend in with the surroundings.
Nano paint currently developing by scientist to make
Invisible of missile, aircraft so it is difficult to detect.
Nano Sensor :
Blue Crab Nano sensors :
What is Chitosan?
A biological compound that readily binds
to negatively charged surfaces
It can interact with a wide
variety of substances and
works well in complex, sensitive
devices, such as Nano sensors
A substance found in
the shell, called
chitosan, is a key
component used in a
Nano sensor, a
“system on a chip” at
the Nano scale
developed at the
explosives, bio agents,
chemicals, and other
dangerous materials in
air and water
This could lead to
security and safety
Bio sensor :
• Incorporates capacitive readout cantilevers and electronics for signal
• sensitive enough to detect single chemical and biological molecules.
Aerospace: Nano sensors can pass through membranes and into white
blood cells, called lymphocytes, to detect early radiation damage or
infection in astronauts.
•DNA molecules attach to the ends
of vertical carbon nanotubes that
are grown on a silicon chip
•These detect specific types of
DNA in an analyze.
Future Challenges In Nano technology
Reducing the cost of materials and devices.
Implication of nanotechnology on society.
Environmental problem can solve.
Innovation of Nano drugs which will be less
side effect and more effective.
• The engineered robots will perform jobs instead of
people which will result in a loss of jobs.
• The wastes released while making the materials
for nanotechnology are released into the atmosphere and
can even penetrate human and animal cells and effect
• Agricultural countries will lose their income as
nanotechnology will take over.
• It has very high initial investment costs along with high
• If any damage is done at the molecular level then it is not
possible to revert it.