A SEMINAR ON NANOTECHNOLOGY

By :Chayon MondalUG IVDept. of Met. and Mat. Engg.Jdavpur University

TOPICS OF INTEREST

Understanding Nanotechnology

Introduction

A Brief History of Nanotechnology

Working Science

Tools used

Applications

Principles for manufacturing

Major sectors

Special Applications

INTRODUCTION – WHAT IS NANOTECHNOLOGY?

•Nanotechnology is the engineering of functional systems at the molecular scale.

• In its original sense, 'nanotechnology' refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products.

Fig. 1 - With 15,342 atoms, this parallel-shaft

speed reducer gear is one of the largest

nanomechanical devices ever modeled in atomic

detail.

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HOW SMALL IS NANO SMALL?

HISTORY OF DEVELOPMENT

1936: Erwin Müller, working at Siemens Research Laboratory, invented the field emission microscope, allowing near-atomic-resolution images of materials.

1959: Richard Feynman of the California Institute of Technology gave what is considered to be the first lecture on technology and engineering at the atomic scale, "There's Plenty of Room at the Bottom" at an American Physical Society meeting at Caltech.

1974: Tokyo Science University Professor Norio Taniguchi coined the term nanotechnology to describe precision machining of materials to within atomic-scale dimensional tolerances.

1981: Gerd Binnig and Heinrich Rohrer at IBM’s Zurich lab invented the scanning tunneling microscope, allowing scientists to "see" (create direct spatial images of) individual atoms for the first time. Binnig and Rohrer won the Nobel Prize for this discovery in 1986.

1985: Rice University researchers Harold Kroto, Sean O’Brien, Robert Curl, and Richard Smalley discovered the Buckminsterfullerene (C60), more commonly known as thebuckyball, which is a molecule resembling a soccerball in shape and composed entirely of carbon, as are graphite and diamond.

1989: Don Eigler and Erhard Schweizer at IBM's AlmadenResearch Center manipulated 35 individual xenon atoms to spell out the IBM logo. This demonstration of the ability to precisely manipulate atoms ushered in the applied use of nanotechnology. (Image at left.)

1991: Sumio Iijima of NEC is credited with discovering the carbon nanotube (CNT), although there were early observations of tubular carbon structures by others as well.

1999-2000s: Consumer products making use of nanotechnology began appearing in the marketplace, including lightweight nanotechnology-enabled automobile bumpers that resist denting and scratching, golf balls that fly straighter, tennis rackets that are stiffer (therefore, the ball rebounds faster), baseball bats with better flex and "kick," nano-silver antibacterial socks, clear sunscreens, wrinkle- and stain-resistant clothing, deep-penetrating therapeutic cosmetics, scratch-resistant glass coatings, faster-recharging batteries for cordless electric tools, and improved displays for televisions, cell phones, and digital cameras.

WHAT MAKES THE NANOSCALE WORKING SO SPECIAL?Scale at which Quantum Effects dominate Properties of Materials - properties such as melting point, fluorescence, electrical conductivity, magnetic permeability, and chemical reactivity change as a function of the size of the particle

Tunability - by changing the size of the particle, a scientist can literally fine-tune a material property of interest

Tunneling - a phenomenon that enables the scanning tunneling microscope and flash memory for computing

Scale at which much of Biology in Nature occurs

hemoglobin, the protein that carries oxygen through the body, is 5.5 nanometers in diameter

A strand of DNA, one of the building blocks of human life, is only about 2 nanometers in diameter

the bio-barcode assay, a relatively low-cost method of detecting disease-specific biomarkers in the blood - attaches “recognition” particles and DNA “amplifiers” to gold nanoparticles

Can also be used for energy – copying the photosynthesis process

New fields of interest - biological principles of molecular self-assembly, self-organization, and quantum mechanics to create novel computing platforms

WHAT MAKES THE NANOSCALE WORKING SO SPECIAL?

Scale at which Surfaces and Interfaces Play a Large Role in Material Properties and Interactions

In other words, a single cubic centimeter of cubic nanoparticles has a total surface area one-third larger than a football field!

WHAT MAKES THE NANOSCALE WORKING SO SPECIAL?

TOOLS USED IN NANOTECHNOLOGY

Atomic Force Microscopy

The AFM was developed in the year 1986 by Binnig, Quate and Gerber at the IBM Research – Zurich and earned them the Nobel Prize for Physics for the same year.

device consists of a mechanical probe that is used to sense the material that is placed on the surface. A highly accurate scanning procedure then takes place, through which the corresponding electronic signals are generated using piezoelectric materials.

TOOLS USED IN NANOTECHNOLOGY

Scanning Tunneling Microscope

Invented in 1981 by

can be used in different modes like air, water, high vacuum, liquid and gas.

Can also be used in very high and low temperatures

Working - The tip of the device is movedcloser to the sample in a controlled manner.At the same time a voltage difference is brought to the tip of the device. As soon asthe tip reaches very close to the material, the voltage difference turns it off.

STRATEGIES TO USE NANOTECHNOLOGY

MANUFACTURING AT NANOSCALE

Top-down approach

reduces large pieces of materials all the way down to the nanoscale, like someone carving a model airplane out of a block of wood

requires larger amounts of materials and can lead to waste if excess material is discarded.

Bottom-up approach

creates products by building them up from atomic-and molecular-scale components

can be time-consuming

Materiaks and devices are constructed from components of their own – chemically reassemble themselves.

The key is to be able to both see and manipulate nanomaterials in order to take

advantage of their special properties.

MANUFACTURING PROCESSES IN NANOTECHNOLOGY

Chemical vapor deposition is a process in which chemicals react to produce very pure, high-performance films

Molecular beam epitaxy is one method for depositing highly controlled thin films

Atomic layer epitaxy is a process for depositing one-atom-thick layers on a surface

Dip pen lithography is a process in which the tip of an atomic force microscope is "dipped" into a chemical fluid and then used to "write" on a surface, like an old fashioned ink pen onto paper

Nanoimprint lithography is a process for creating nanoscale features by "stamping" or "printing" them onto a surface

Roll-to-roll processing is a high-volume process to produce nanoscale devices on a roll of ultrathin plastic or metal

Self-assembly describes the process in which a group of components come together to form an ordered structure without outside direction

A product of nanomanufacturing: A 16

gauge wire (above), approximately

1.3 millimeters in diameter, made

from carbon nanotubes that were spun

into thread. And the same wire on a

150 ply spool (below.) Courtesy of

Nanocomp.

APPLICATIONS : ADVANCED MATERIALS

Advanced materials, such as metallic glasses, nanomaterials,

biomaterials, smart materials, semiconductors, nanocomposites etc., are

used in different industrial, medical, electronic, and many other sectors

are preparedby wide variety of materials.

APPLICATIONS : EVERYDAY MATERIALSNano-engineered materials in automotive products include high-power rechargeable battery systems; thermoelectric materials for temperature control; lower-rolling-resistance tires; high-efficiency/low-cost sensors and electronics; thin-film smart solar panels; and fuel additives and improved catalytic converters for cleaner exhaust and extended range.

Nanoscale thin films on eyeglasses, computer and camera displays, windows, and other surfaces can make them water-repellent, antireflective, self-cleaning, resistant to ultraviolet or infrared light, antifog, antimicrobial, scratch-resistant, or electrically conductive.

Nano-engineered materials in the food industry include nanocomposites in food containers to minimize carbon dioxide leakage out of carbonated beverages, or reduce oxygen inflow, moisture outflow, or the growth of bacteria in order to keep food fresher and safer, longer. Nanosensors built into plastic packaging can warn against spoiled food. Nanosensors are being developed to detect salmonella, pesticides, and other contaminates on food before packaging and distribution.

Nanoparticles are used increasingly in catalysis to boost chemical reactions. This reduces the quantity of catalytic materials necessary to produce desired results, saving money and reducing pollutants. Two big applications are in petroleum refining and in automotive catalytic converters.

Fig. High-resolution image of a

polymer-silicate nanocomposite. This

material has improved thermal,

mechanical, and barrier properties

and can be used in food and

beverage containers, fuel storage

tanks for aircraft and automobiles,

and in aerospace components.

(Image courtesy of NASA.)

APPLICATION : CONSTRUCTION MATERIALS

Self-healing concrete or Bio-concrete : Lime producing bacteria mixed with concrete, which lie dormant, but when water and sunlight seeps through cracks, become active secreting lime and repairing the concrete. Similar to osteoplast cells in the body.

Addition on nano-silica particles to concrete – stabilizes the Calcium-Silicate-Hydrate bond from Calcium leaching, as well as increases compressive strength.

Addition of TiO2 in paint coatings on buildings breaks down organic pollutants by catalytic reactions. TiO2 is also hydrophilic, thus provides self-cleaning properties.

APPLICATIONS : SUSTAINABLE ENERGY

Prototype perovskite solar panels incorporating nanotechnology are more efficient than standard designs in converting sunlight to electricity, promising inexpensive solar power in the future. The efficiency limit of perovskite solar cells is about 31%, which approaches the Shockley–Queisser limit of gallium arsenide (33%).

Nanostructured materials are being pursued to greatly improve hydrogen membrane and storage materials and the catalysts needed to realize fuel cells for alternative transportation technologies at reduced cost. Researchers are also working to develop a safe, lightweight hydrogen fuel tank

Prototypes of Li-ion batteries grouped with viruses (Fig.) that have same capacity but greater efficiebcy than Li-ion batteries. The viruses recognize and bind specifically to certain materials (carbon nanotubes in this case), each iron phosphate nanowire can be electrically "wired" to conducting carbon nanotube networks. Electrons can travel along the carbon nanotube networks, percolating throughout the electrodes to the iron phosphate and transferring energy in a very short time.

REFERENCES :

http://www.nano.gov/

http://news.mit.edu/2009/virus-battery-0402

http://www.smithsonianmag.com/innovation/with-this-self-healing-concrete-buildings-repair-themselves-180955474/?no-ist

Mechanical Alloying – M. Sherif El-Eskandaranyhttps://books.google.co.in/books?id=kwjGAgAAQBAJ&printsec=frontcover#v=onepage&q&f=false

Wikipedia

http://www.circuitstoday.com/nanotechnology-tools-and-instruments

THANK YOU.