The document provides an overview of nanotechnology, defining it as the manipulation of materials at the nanoscale (1-100 nanometers) and detailing its applications in electronics, medicine, and various industries. It discusses the properties of nanomaterials, particularly carbon nanotubes, and their structural types, as well as the benefits and challenges associated with nanotechnology, including potential health risks and environmental impacts. The text emphasizes the revolutionary potential of nanotechnology while also acknowledging its considerable costs and dangers.

1. Subject Name And Code : Physics(2110005)
Active Learning Assignment
Topic : Nanotechnology
Guided by : Sanket sir
Branch : Electrical
Division : F2 Sem : 1st
Academic Year : 2014(odd)

3. What is Nanotechnology ?
 The branch of technology that deals with dimensions and tolerances of less
than 100 nanometres, especially the manipulation of individual atoms and
molecules.
 Nanotechnology is the technique of design , production of devices and system
by controlling the shape and size at the nanometre scale.

4. Nanomaterial
 Nanomaterials are the materials containing nanocrystals, i.e.
their grain size is in the 1 to 100 nanometre range. The
material may be metals, alloys, intermetallic and ceramics .
 In commercial products they are used for a electronic
devices, sporting goods, cosmetics, textiles, sunscreens,
tyres , paint, vanishings etc. In medical field, they are used
for the purpose of imaging, targeted drug delivery, diagnosis
etc.

5. Nanoscale
 The nanoscopic scale (or nanoscale) usually refers to structures with a
length scale applicable to nanotechnology, usually cited as 1–100 nanometres.[
1] A nanometre is a billionth of a meter. The nanoscopic scale is (roughly
speaking) a lower bound to the mesoscopic scale for most solids.
 For technical purposes, the nanoscopic scale is the size at which fluctuations in
the averaged properties (due to the motion and behavior of individual
particles) begin to have a significant effect (often a few percent) on the
behavior of a system, and must be taken into account in its analysis.
 The nanoscopic scale is sometimes marked as the point where the properties of
a material change; above this point, the properties of a material are caused by
'bulk' or 'volume' effects, namely which atoms are present, how they are
bonded, and in what ratios. Below this point, the properties of a material
change, and while the type of atoms present and their relative orientations are
still important, 'surface area effects' (also referred to as quantum effects)
become more apparent – these effects are due to the geometry of the material
(how thick it is, how wide it is, etc.), which, at these low dimensions, can have
a drastic effect on quantized states, and thus the properties of a material.

7. Surface Area To Volume Ratio
 The surface-area-to-volume ratio, also called the surface-to-volume
ratio and variously denoted sa/vol or SA:V, is the amount of surface area per
unit volume of an object or collection of objects. The surface-area-to-volume
ratio is measured in units of inverse distance.
 SA:V is a great way to measure the efficiency of nanotechnology.
 SA:V In a nanoparticle have a significant effect on nanoparticle properties.
 As an example, a cube with sides of length a will have a surface area of
6a2 and a volume of a3. The surface to volume ratio for a cube is thus shown as

8. What is a Carbon Nanotube?
• Nanotubes have been constructed with length-to-diameter
ratio of up to 132,000,000.
• A carbon nanotube is a cylindrical rolled up sheet of
graphene mostly closed at the ends. The rolled structure is
a single molecule nanotube is a made of hexagonal
network structure of covalently bonded carbon atoms.
Rolled graphite
sheet to obtain CNT

9.  Then hexagonal structure gives them great stencil strength and elastic
property.
 Nanotubes are member of the fullerene structure family, which also includes
the spherical Bucky ball. the end of a nanotube may be capped with a
hemisphere of the Bucky ball structure. This are simply called as “caps” or
“end caps”. Caps contained six pentagons (half the number in C60 fullerene)
and different number of hexagons so that they can fit on the tubes properly.
Carbon nanotubes are categorised as , single walled carbon
nanotubes(SWCNTs) and multi walled carbon nanotubes(MWCNTs ,i.e. , tubes
with a many concentric cylinders of graphite).
 A SWCNT can have a diameter of 2nm and a length of 100um, making it
effectively a one dimensional structure called a nanowire.
 Both SWCNT and MWCNT have their own range of applications.

10. STRUCTURE OF CARBON NANOTUBES
1. Arm chair CNT
. The arm chair structure with arrangement of carbon atoms can be seen fig.
These are formed when T is parallel to C-C bonds of carbon hexagons and for
the chiral angle θ=π/6 and chirality(a,a).This type of tubes are achiral tubes ,
i.e., their mirror images are similar as the original structure .The arm chair
type is always metallic.

11. 2. Zigzag CNT
 The zigzag CNT shown in a figure. These are formed by a rolling about a T
vector having different orientation in the graphite plane but not parallel to C-C
bonds and for chiral angel Q = 0. and Chirality (a,0)., i.e. , by folding
parallel to x-axes. It can be seen from the figure , the zigzag aligned of
carbon atoms. Hence the name zigzag CNT. This type of tube also achiral in
nature. This tube can be either metallic or semi-conducting based on their
chiral condition.

12. 3. Helical or chiral CNT
 These are obtained when chiral angle q is anywhere between 0 and π/6 and
chirality is a (a,b). The helical structure of CNT is shown in figure. These
tubes are chiral tubes., i.e. their mirror images appear to differ from their
original structure.

13. Why Now ?
Richard Feynman’s famous presentation “There’s Plenty of Room at
the Bottom” was in the 1959 at the American Physical Society.
Here he asked:
Why can’t we manipulate materials atom by atom?
 Why can’t we control the synthesis of individual molecules?
Why can’t we write all of human knowledge on the head of a pin?
Why can’t we build machines to accomplish these things?
 New tools for atomic-scale characterization
 New capabilities for single atom/molecule manipulation
 Computational access to large systems of atoms and long time
scales
 Convergence of scientific-disciplines at the nanoscale

14. Benefits of Nanotechnology
 “The power of nanotechnology is rooted in its potential to
transform and revolutionize multiple technology and industry
sectors, including aerospace, agriculture, biotechnology,
homeland security and national defense, energy, environmental
improvement, information technology, medicine, and
transportation. Discovery in some of these areas has advanced to
the point where it is now possible to identify applications that
will impact the world we live in.”

15. Importance of Nanotechnology
 Various properties of materials such as electronics, thermal, mechanical,
optical and chemical have been vastly improved at the nanoscale.
 Therefore it is possible to achieve exceptional performance in components
and devices.

16. 2 GB in 1980s $80,000
2 GB in 1990s $200
2 GB in 2010 $5
Current research
shows that by using
nanotechnology,
1000 GB of memory
can fit on the head
of this pin. 1000 GB
is 1 Terabyte.

17. Carbon nanotubes on a glass or
plastic sheet allow
manufacturers to make clear
conductive panels for displays
that are extremely thin.
Instead of making
transistor components and
assembling them on a
board, nanoscale
transistors are grown
together on a silicon wafer.
They look much different
from the traditional
transistors.
Transistors
Nano Transistor

18. Disadvantages of Nanotechnology
 Atomic weapons can now be more accessible and made to be
more powerful and more destructive. These can also become
more accessible with nanotechnology.
 Presently, nanotechnology is very expensive and developing it can
cost you a lot of money. It is also pretty difficult to manufacture,
which is probably why products made with nanotechnology are
more expensive.
 Nanotechnology has increased risk to the health also ,
nanoparticles due to there their small size can cause inhalation
problem and many other fatal diseases. by just inhaling for 60
seconds in the air contain nano particles can damage lungs easily.
 The engineered robots will perform jobs instead of people which
will result in a loss of jobs
 If any damage is done at the molecular level then it is not possible
to revert it.

19. Future Challenges Using Nanotechnology
 Environmental problems can be solved.
 Efficiency of renewable sources can be greatly improved.
 It may help to grow life in order space/planet.
 It helps in sustaining the planet for future generation.

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