Nano technology

1. Asad Ali

2. Introduction
“Nanotechnology is the art and science of
manipulating matter at the Nano scale.

3. Introduction
 This concept is based on nanometer scale.
 The dimension approximately from 1nm to 10 nm is
called nanoscale.
 It is the most advanced technology of the modern
world.
 Nanotechnology found the size of the cells.
 Human hair is approximately 8000 nm wide.
 Sheet of paper is 100000 nm thick
 Gold atom is about 1/3 nm in diameter.

4. Introduction
A nanometer is one billionth of a meter.
The size of DNA is 2nm.

7. Applications
 1: Sunscreens:
UVB exposure…..
 Sun Burn


8. Applications
 Carcinomas

9. Application
 TiO2 and ZnO nanoparticles provide broad spectrum
UV pretection.

10. Applications
 2: Photocatalysis.
 Photocatalytic reactions can purify:
 Water
 Air
 Surfaces etc
 TiO2 nanocrystals are used.

12. Photocatalysis
 Also use in self cleaning or antifogging.

13. Applications
 3: Propellant:
 The 502126 kg of propellant use in
the solid rocket booster of the space
shuttle.
 16 % i.e 80340 kg is atomized nano
aluminum powder .

14. Applications
 4: Drugs delivery and disease treatment.
Cancer treatment.
Nano crystals target the cancer cells to destroy it.

16. NANO FABRICATION
 Nanofabrication is the design and manufacture of
devices with dimensions measured in nanometers.

17. METHODS OF NANOFABRICATION
 There are two methods of nanofabrication.
 Top-down methods
 Bottom-up methods

18. TOP-DOWN METHOD
 Begin with a pattern generated on a larger scale, then
reduced to nanoscale.
 By nature, aren't cheap and quick to manufacture.
 Slow and not suitable for larger scale production.
 The following few methods are top-down

19. TOP-DOWN METHOD
1) Arc discharge method.
When pure graphite rods are used,
fullerenes are deposited as soot inside the
chamber, and multi-walled carbon
nanotubes are deposited on the cathode.
When a graphite anode containing a metal
catalyst (Fe or Co) is used with a pure
graphite cathode single-walled carbon
nanotubes are generated in the form of
soot.

20. Arc discharge

21. TOP-DOWN METHOD
2) Laser ablation method:
Laser ablation is the process of
removing material from a solid (or
occasionally liquid) surface by
irradiating it with a laser beam. At
low laser flux, the material is heated by
the absorbed laser energy and
evaporates or sublimates.

24. TOP-DOWN METHOD
3) Ball milling:
A ball mill is a type of grinder used to
grind and blend materials for use in
mineral dressing processes, paints,
pyrotechnics, ceramics and selective
laser sintering.

26. BOTTOM-UP METHOD
Bottom-up starts with atoms or molecules and build up to
nanostructures.
Fabrication is less expensive here.

27. BOTTOM-UP METHOD
 Bottom methods are:
1) Chemical vapor
deposition:(CVD)
is a chemical process used to produce
high quality, high-performance, solid
materials. The process is often used in
the semiconductor industry to
produce thin films.

29. BOTTOM-UP METHOD
2) Sol-Gel synthesis:
The method is used for the fabrication
of metal oxides, especially the oxides
of silicon and titanium. The process
involves conversion of monomers into
a colloidal solution (sol) that acts as
the precursor for an integrated
network (or gel) of either discrete
particles or network polymers.

31. BOTTOM-UP METHOD
3) Molecular beam epitaxy:
Molecular beam epitaxy (MBE) is
an epitaxy method for thin-film
deposition of single crystals. It was
invented in the late 1960s at Bell
Telephone Laboratories by J. R. Arthur
and Alfred Y. Cho.