NANOTECHNOLOGY By Saurabh Chawla XII Science FAITH ACADEMY
An engineered DNA strand What is Nanotechnology? “ Nanotechnology is the art an science of manipulating matter at the nanoscale ” Buckyball
Nano technology is the study of making small microscopic things
It is an advance to the future
What is Nanoscale? 0.22 m Fullerenes C 60 22 cm 0.7 nm 10 millions times smaller 1 billion times smaller 12,756 km 1.27 × 10 7 m 0.7 × 10-9 m
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 Microscope. This microscope evolved to allow the manipulation of individual atoms and molecules in the field of Nano technology.
1985 – “Buckyball” - Scientists at Rice University and University of Sussex discover C 60
1991 – Carbon nanotube discovered by S. Iijima
History of Nanotechnology
NEED FOR NANOTECHNOLOGY
Allows the placement of small structures placed with precision,simplicity and low cost
Leads to economic growth
Enhances national security
Improves the quality of life
Leads to job creation
APPROACHES OF NANOTECHNOLOGY
Nanoscale Approaches and Fabrication Top-down Approaches Bottom-up Approaches Create smaller objects using Larger objects They arrange smaller components in to more complex. Uses principles of molecular recognition Layer-by-layer self assembly
Nanotechnology Applications Stinger: Targeted Drug Delivery
Nanorobot Aerogel NANO FILTERS Nano Transistor
With NT, we can create unique materials and products which
Computers can become a billion times faster and a million times smaller
Automatic Pollution Cleanup
Manufacturing at almost no cost
End of Illnesses (i.e. cancer, heart disease)
Universal Immunity (i.e. aids, flu)
(i.e. change your appearance)
Industrial Medical Material Advantages
FULLERENES Buckminster fullerene
Single walled nanotube
Multi walled nanotube
SINGLE WALLED NANOTUBE:
MULTI WALLED NANOTUBE:
Carbon NanoTubes The joining of two carbon nanotubes
Carbon Nanotubes:: This rotating picture is actually a model of carbon nanotube, the strongest and stiffest materials discovered till to date.
CNTs also known as buckytubes are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1
Single Walled Nanotubes (SWNT) The ( n , m ) nanotube naming scheme can be thought of as a vector ( C h ) in an infinite graphene sheet that describes how to "roll up" the graphene sheet to make the nanotube.
Single-walled nanotubes have a diameter of close to 1 nanometer, with a tube length that can be many millions of times longer.
The structure of a SWNT can be conceptualized by wrapping a one-atom-thick layer of graphite called graphene into a seamless cylinder.
The way the graphene sheet is wrapped is represented by a pair of indices ( n , m ) called the chiral vector
Single-walled nanotubes are an important variety of carbon nanotube because they exhibit electric properties
There are two models of description of these MWNT::
In the Russian Doll model, sheets of graphite are arranged in concentric cylinders
In the Parchment model, a single sheet of graphite is rolled in around itself, resembling a scroll of parchment or a rolled newspaper
Multi Walled Nano Tubes (MWNT)
Multi-walled nanotubes (MWNT) consist of multiple rolled layers (concentric tubes) of graphite
A nanotorus is theoretically described as carbon nanotubes bent into a torus (doughnut shape).
Nanotori are predicted to have many unique properties, such as ‘ magnetic moments’ which is the property of magnet that interacts with an applied field to give a mechanical moment
Carbon nanobuds are a newly created material combining two previously discovered allotropes of carbon: carbon nanotubes and fullerenes
This hybrid material has useful properties of both fullerenes and carbon nanotubes .
A stable nanobud structure
Properties of Nano Tubes
Strength :- Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively.
Hardness :- The hardness of compressed SWNTs is 462–546 GPa, surpassing the value of 420 GPa for diamond
Electrical :- In theory, metallic nanotubes can carry an electrical current density of 4 × 10 9 A/cm 2 which is more than 1,000 times greater than metals such as copper.
Thermal :- All nanotubes are expected to be very good thermal conductors along the tube, the temperature stability of carbon nanotubes is estimated to be up to 2800 °C in vacuum and about 750 °C in air.
Striking properties of nanoparticles:
Tremendous driving force for diffusion
Quantization of electronic energy levels
IMPLEMENTATIONS OF NANOTECHNOLOGY
Nanorobot repairing RBC
Solar cells developed at the New Jersey Institute of Technology use a carbon nanotube complex, formed by a mixture of carbon nanotubes and carbon buckyballs
With a nanotube electrode the hollow spaces that store charge may be tailored to any size and consequently the capacity should be increased considerably .
A paper battery is a battery engineered to use a paper-thin sheet of cellulose infused with aligned carbon nanotubes. The nanotubes act as electrodes; allowing the storage devices to conduct electricity. The battery, which functions as both a lithium-ion battery and a supercapacitor, can provide a long, steady power output comparable to a conventional battery .
Carbon nanotubes have been implemented in nanoelectromechanical systems, including mechanical memory elements (NRAM being developed by Nantero Inc.)
Applications of Nano Tubes Aligned nanotubes are preferred for many applications.
APPLICATIONS OF NANOTECHNOLOGY
In curing diseases like AIDS
To make new surgical devices
Changing the untasteful medicine into tasteful
Nano products can be prepared at average sized homes
ADVANTAGES OF NANOTECHNOLOGY
Low production cost
Mass production in food & consumables
DISADVANTAGES OF NANOTECHNOLOGY
Health and safety issues
Nanoparticles can cause serious illness or damage human body.
Untraceable destructive weapons of mass destruction.
Social & Political issues
Creates social strife through increasing wealth gap
Advisability of increasing scope of the technology creates political dilemma
Implications of Nanotechnology
Exposure of human and the environment to nanomaterials at different stages of product life cycle
“ Grey-goo ”
It is a hypothetical situation where self replicating nanobots go out of control, and consume all matter on earth.
Nanopollution is created by toxic wastes from nanomaterial manufacturing
Enhances Global warming in the long run
“ The Living Fog ” formed by billions of replicating nanobots gone mad