This document provides an introduction to nanotechnology. It discusses how properties of materials change at the nanoscale level and provides examples of current and potential nanotechnology applications. Key points include: - Properties of materials such as optics, electricity, and reactivity behave differently at the nanoscale compared to bulk materials. - Nanotechnology could enable scientific breakthroughs in fields like engineering materials with atomic precision, creating molecular circuits and devices, and developing improved medical diagnostics and drug delivery systems. - Current applications of nanotechnology include nanomaterials used in electronics, medicines, sunscreens, and catalysts. Potential future applications discussed are in fields like computing, energy, space travel, manufacturing, sports, clothing, cosmetics, health

1. AN INTRODUCTION TO
NANOTECHNOLOGY
“THE NEXT BIG THING IS REALLY
SMALL”
By S D Ramesh
Department of Physics
VIJAYA COLLEGE JAYANAGAR.
1

2. Properties of a Material
A property describes how a material
acts under certain conditions
Types of properties
 – Optical (e.g. color, transparency)
 – Electrical (e.g. conductivity)
 – Physical (e.g. hardness, melting point)
 – Chemical (e.g. reactivity, reaction rates)
Properties are usually measured by
looking at large (~1023) aggregations
of atoms or molecules

3.  Optical Properties Example: Gold
Bulk gold appears yellow in color
Nanosized gold appears red in color
The particles are so small that electrons
are not free to move about as in bulk gold
Because this movement is restricted, the
particles react differently with light

5.  Scale Changes Everything
There are enormous scale differences
in our universe!
At different scales Different forces
dominate
Different models better explain
phenomena

6. Scientific breakthroughs that may be
enabled by nanotechnology
• Engineer materials with atomic precision using biosystems as agents
• Create circuits with logic element a molecule wide
• Assemble DNA, nanocrystals to build molecular devices and systems
• Detect toxins and contaminants in air, water, or soil with unprecedented speed
and accuracy
• Single molecule behavior and interaction
• Artificial genetic system
• Conducting polymers
• New concepts for large scale production of nanotubes, their use
• Drug delivery systems
• Detection of cancer

7. What happens at the nanoscale?
• At the nanoscale, the physical, chemical, and
biological properties of materials differ in
fundamental and valuable ways from the properties
of individual atoms and molecules or bulk matter.
• Nanotechnology R&D is directed toward
understanding and creating improved materials,
devices, and systems that exploit these new
properties.

8. Current nanotech applications &
products
• Nanomaterials, in general, used for electronic,
magnetic and optoelectronic, biomedical,
pharmaceutical, cosmetic, energy, catalytic
applications
• Nanoparticles, in particular, used for chemical-
mechanical polishing, magnetic recording tapes,
sunscreens, automotive catalysts, biolabeling,
electroconductive coatings and optical fibers

9. • Superior, lightweight materials: Imagine materials ten times
stronger than steel at a fraction of the weight. With such
materials, nanotechnology could revolutionize tanks, airframes,
spacecraft, skyscrapers, bridges, and body armor, providing
unprecedented protection. Composite nano-materials may one
day lead to shape-shifting wings instead of the mechanical flaps
on current designs. Kevlar, the backbone fiber of bulletproof
vests, will be replaced with materials that not only provide
better protection but store energy and monitor the health status
of our soldiers. A taste of what’s to come: MIT was awarded a
$50 million Army contract in 2002 to launch the Institute for
Soldier Nanotechnologies (ISN) developing artificial muscles, bio
warfare sensors, and communications systems.

10. Advanced computing: More powerful and
smaller computers will encrypt our data and
provide round-the-clock security. Quantum
cryptography
— cryptography that utilizes the unique properties
of quantum mechanics — will provide unbreakable
security for businesses, government, and military.
These same quantum mechanics will be usedto
construct quantum computers capable of breaking
current encryption

11. Seeing is Believing: In 1981, Gerd Binnig and
Heinrich Rohrer of IBM’s Zurich Research
Laboratory create the scanning tunneling
microscope,
enabling researchers to both see and manipulate
atoms for the first time.
Nanostructures: In 1985, Robert F. Curl Jr.,
Harold W. Kroto, and Richard E.
Smalley discover buck minster fullerenes soccer-
ball-shaped molecules made of carbon and
measuring roughly 0.7nm wide.

12. SMART materials:
Smart materials are the materials that
have one or more properties that can be
significantly altered in a controlled
fashion by external stimuli such as
stress, temperature, moisture, electric
and magnetic fields. Some of them are

13. "Smart" materials respond to environmental stimuli
with particular changes in some variables. For that
reason they are often also called responsive materials.
Depending on changes in some external conditions,
"smart" materials change either their properties
(mechanical, electrical, appearance), their structure or
composition, or their functions.
Mostly, "smart" materials are embedded in systems
whose inherent properties can be favorably changed
to meet performance needs.

14.  Piezoelectric materials
Thermo responsive materials
 pH sensitive materials
 Chromogenic materials

15. Piezoelectric effect:They produce an electric field when
exposed to a change in dimension caused by an
imposed mechanical force (piezoelectric or generator
effect). Conversely, an applied electric field will produce
a mechanical stress (electro-strictive or motor effect).
They transform energy from mechanical to electrical
and vice-versa.The stress is very small, 0.1-0.3%.They
are used for sensing purposes (e.g. microphone,
transducer), and for actuating applications.
Similar to piezoelectric materials are electrostrictive
and magnetostrictive materials used in high prescision
actuation.They are ferromagnetic materials which
experience an elastic strain when subjected to an
electric or magnetic field respectively.

16. Thermo-chromic materials:Thermo-chromic
materials change color with changes in
temperature.
They can be made as semi-conductor
compounds, from liquid crystals or using metal
compounds.The change in color happens at a
determined temperature, which can be varied
doping the material.
They are used to make paints, inks or are mixed
to moulding or casting materials for different
applications.

17. Electroluminescent materials produce a
brilliant light of different colors when
stimulated electronically (e.g. by AC current).
While emitting light no heat is produced.
Like a capacitor the materials is made from an
insulating substance with electrodes on each
side. One of the electrodes is transparent and
allows the light to pass.The insulating
substance that emits the light can be made of
zinc sulphide or a combination
They can be used for making light stripes for
decorating buildings, or for industrial and public
vehicles safety precautions.

18. Photo-chromic materials change color with
changes in light intensity.
Usually, they are colorless in a dark place, and
when sunlight or ultraviolet radiation is applied
molecular structure of the material changes and it
exhibits color. When the relevant light source is
removed the color disappears.
Changes from one color to another color are
possible mixing photo-chromic colors with base
colors.They are used in paints, inks, and mixed to
mould or casting materials for different
applications.

19. Shape-Memory Alloys : Shape-Memory Alloys
are metals that, after being strained, at a certain
temperature revert back to their original shape.
A change in their crystal structure above their
transformation temperature causes them to
return to their original shape.
SMAs enable large forces (generated when
encountering any resistance during their
transformation) and large movements
actuation, as they can recover large strains.

20. • Polypyrrole coatings (conducting polymers) on
fabrics mean that the electrical conducting properties
of the fabrics themselves change as they are
subjected to physical stretching or compression.
• If we coat foam or lycra with polypyrrole and use this
in wearable garments , functionalise specific locations on the
garment to sense stretching, bending, pressure or other fabric
movement;
• Integrating these smart materials into
clothing to monitor breathing, limb movements and
posture in vests, t-shirts, arm bands etc., and in
shoes to monitor steps/activity;
• Used in applications in sports performance
monitoring, posture sensing and in dance/yoga-
exercise applications
Smart Materials - Physical

21. Nanoparticles
• Vitamins
• Sunscreen
• Using aluminum
nanoparticles to create
rocket propellants that
burn at double the rate.
• Nano particulate
synthetic bone.

22. Nanocatalysts
• Liquefy coal into gas
• Catalyst: Gel based
nanoscale catalyst
Impact
• Reduce acid rain
• Dependency on less
foreign fuel

23. Nanofilter
• Filter the smallest
particles.
• Nano sized Alumina
fiber mesh
• Water filtration
• Air Filtration
• Sterilization

24. Smart Dust
• Tiny bottle-cap-shaped
micro machines fitted with
wireless communication
devices.
• Application
– Monitoring humidity to
assess freshness of food
– Monitoring
quadriplegics’ eye
movements and facial
gestures to assist in
wheel chair operation.
– Detecting cancer.
– Road assistance.

25. MEMS
• Integration of mechanical elements,
sensors, actuators and electronics
on a common silicon substrate.
• System on a chip possible
• Brains, eyes and arms in one
system.

26. Spintronics
• Using the spin of the
electron rather than its
charge for transport of
charge
• More compact and robust
devices

27. Nanotubes
Profile
• Known as carbon nanotubes or nanowires (non-carbon)
• Cylindrical wall with atoms arranged in hexagonal or pentagonal faces
• Strength and strain
• Properties of conductors, semiconductors or insulators
• High thermal conductivity
• Dimensions: 0.4 nm in diameter

28. “It’s got strength and endurance.”
• 100 times stronger than steel at one-sixth of the weight
• Tensile strength: 200 Giga Pascal
• Stiff as diamond – Young’s modulus over 1 Tera Pascal
• Multi-walled nanotubes
• Reinforced composites – transportation industry? Aerospace?
Carbon Nanotubes

29. MEMS (Applications)
• Accelerometers for airbags
• Micro heat exchangers
• Sensors
• Actuators
• Micropumps

30. NEMS (Application)
• Nano-structured Catalysts
• Drug Delivery systems
• Molecular Assembler/Replicators
• Sensors
• Magnetic Storage Applications
• Reinforced Polymers
• Nano-fluids

31. Applications for
Nanotechnology
• Cost and performance of space travel will
be improved significantly.
• Computers will be more powerful.
• Weapons will be capable of greater
precision and control.
• Solar energy will provide for the world’s
future needs.
• Surgical tools will be improved.

32. • Cell phones with longer battery life
• Global Positioning Systems that are smaller and more
accurate
• Computers that are faster and smaller
• Memory storage that packs greater capacity into
a smaller space and uses less energy
• DNA fingerprinting that is quick and accurate

33. STM Image of Nickel Atoms and
IBM written using Xenon atoms

34. Computing and Data Storage
• Processors with declining energy use and cost thus increasing efficiency of
computers by one million.
• Small mass storage devices
• Integrated nanosensors: Collecting, processing and communicating massive
amounts of data with minimal size, weight, and power consumption
• Higher transmission frequencies and more efficient utilization of optical
spectrum to provide at least 10 times the bandwidth
• Quantum computing
• Display technologies: Flat-panel displays forTV and video screens that may one
day be thinner than a sheet of paper

35. Electronics Products
• Samsung 8 GB compact flash card
“This flash memory unit boasts a fat 8
gigabytes of memory, room for loads of
songs, photos and PowerPoint
presentations.”
• OLED digital camera
“Organic light-emitting diodes (OLEDs)
are much brighter than the liquid
crystals (LCDs) used in many of today's
flat-screenTVs and computer monitors.
They boast a wider viewing angle than
LCDs, which must be viewed head-on.
OLEDs don't require backlighting as
LCDs do, reducing power consumption”

36. Materials and Manufacturing
• Manufacturing metals, ceramics, polymers at exact shapes without
machining
• Lighter, stronger and programmable materials
• Lower failure rates and reduced life-cycle costs
• Bio-inspired materials
• Multifunctional, adaptive materials
• Self-healing materials
• Self-cleaning surfaces (e.g., windows) (‘smart surface’ of nanometer-
high ‘mushrooms’ that absorb or repel water at the flick of a switch)
• FUTURE: “Smart” materials that can change color or shape and,
perhaps, even assemble themselves

37. Materials Manufacturing Products
• Hummer H2 sport utility truck
“Made with about seven pounds
of nanocomposite material, the
cargo bed Hummer's H2 SUT is
lighter and more scratch proof
than older plastics. Besides the
weight advantage, GM says the
nanocomposite parts don't
change shape when exposed to
temperature changes.”
• Self-cleaning concrete
“An exterior view shows U.S.
architect Richard Meier's Jubilee
Church, located in the Tor Tre
Teste area of Rome, in this 2003
file photo. It is made of self-
cleaning concrete that helps keep
the surface shiny white.”

38. Sports Products
• Tennis rackets
“The Nanotube Power andVS Nanotube Drive lightweight,
oversized-head models are made out of high modulus graphite with
carbon nanotubes. . . One hundred times stronger than steel, yet
one-sixth the weight, carbon nanotubes increase the rigidity of the
stabilizers on each side of the racket's sweet spot. . .VS Nanotube
rackets are five times more rigid than current carbon rackets and
pack significantly more power.” Tennis balls
• NanoDynamics golf ball
“This ball is engineered with nanoparticles to spin less, which should
mean less slices and hooks.The bad news? Lower spin could mean
shorter drives.”
• Stronger golf clubs
• More accurate bowling balls

39. Clothing Products
“In the clothing world, we have pants that repel water and won’t stain shirts
and shoe inserts that keep you cool in the summer and warm in the winter,
and nano socks that don’t “stink” due to the inclusion of nanotech materials
(nanosized sliver particles
•Breathable waterproof ski jacket
“Nanotechnology makes the two-layer laminate windproof,
waterproof, breathable and grime resistant--great for those bums who
don't get around to washing their jackets until after the season. The
result: a jacket with a long, functional life superior to coated jackets and
competitive with Gore-Tex products
•Wrinkle-resistant, stain-repellent threads
“Nano-Tex researchers attached molecular structures to cotton fibers,
forming a barrier that causes liquids and stains to bead up on the
surface and prevent absorption.Treated fabrics are not only wrinkle-
proof but repel stains from perennial offenders like soda, coffee, wine,
mayonnaise and syrup.”
•Color-changing fabrics
Thread developed for military but may soon be used by clothing
companies.

40. Cosmetics Products
• Skin care
“L’Oreal's Plenitude line of cosmetics contains
nanocapsules, which help active ingredients get to the
skin's deeper layers.The nanocapsules are also in
L'Oreal's higher-end brands such as Lancome.”
“Novasome” capsules can deeply penetrate skin and
don't degrade while on the shelf
• Nanocrystalline Sunscreen
“Its main ingredient is Z-COTE, a substance made with
nanotechnology . . . Nano-dispersed zinc oxide. . . .
Zinc oxide provides broad-spectrum protection against
UVA and UVB rays, but its characteristic white pasty
goop often leaves sunbathers and lifeguards feeling
like they're wearing clown makeup. The
nanotechnology in Z-Cote produces a high-purity
nanocrystalline zinc oxide, which allows the sunscreen
to go on clear.”

41. Products with Protective Coatings
• Glare-reducing and fog-resistant coatings for eyeglasses
and windshields
• Sunglasses
“To give the glasses antireflection and scratch-resistance functionality,
Nanofilm deposits coating layers of 150 nanometers and 20 microns
thick, respectively.Then it uses chemical self-assembly to form a
polymer coating, three to ten nanometers thin, on the outer layer of
the antireflective lenses.This not only seals and repels grime and skin
oils but also makes the lenses more responsive.“
• High-Performance Ski Wax
“Nanowax produces a hard, fast-gliding surface.The ultrathin coating
lasts much longer than conventional waxing systems, while leaving
the base free of buildup.And here's the "intelligent" part: Cerax
Nanowax hardens as temperatures drop, adapting to the ski bases and
snow crystals, so you can reach top speed from the first few feet on.”
• No-wax car finish--for example, by Mercedes.

42. Health and Medicine Products
• LabNow Blood Analyser
“Tiny channels in a card filter white from red
blood cells.When the card is popped into
the analysing machine, it can come up with
a white-cell count in 10 to 15 minutes.This
could be important for HIV/Aids treatment
Bandages embedded with silver
nanoparticles
• Drug delivery via a patch
• Thin films on implantations into the human
body (for example screws, joints, and stents)
allowing devices to last longer
• Respiration monitors that are many times
more sensitive
• Man-made skin for skin graft applications.

43. Nanotechnology R&D is
interdisciplinary and impacts many industries
• Physics
• Chemistry
• Biology
• Materials Science
• Polymer Science
• Electrical Engineering
• Chemical Engineering
• Mechanical Engineering
• Medicine
• And others
• Electronics
• Materials
• Health/Biotech
• Chemical
• Environmental
• Energy
• Aerospace
• Automotive
• Security
• Forest products
• And others

44. SUMMERY
• Nanotechnology is inherently an interdisciplinary
field that encompasses physics, chemistry, biology,
and engineering.
• Recent years (and months) have seen significant
scientific and technological advances in
nanotechnology.
• The government and industry are investing heavily
in nanotechnology research and development.
• Many future developments and technologies have
been
promised – are they realizable?