nanotechnology 3

8/6/2019 Nanotechnology 3

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NANOTECHNOLOGYBy

K. Satya Sushma N. SatyaDevi

I.TBapatla Engineering College

[email protected] [email protected]
mailto:[email protected]:[email protected]


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Introduction:

Imagine a technology so powerful that it will allow

such feats as desktop manufacturing, cellular repair,

artificial intelligence, inexpensive space travel,

clean and abundant energy and environmental

restoration; a technology so portable that every one

can reap its benefits; a technology so fundamental

that it will radically change the economic and

political systems; a technology so imminent thatmost of people will see its impact within the

lifetimes. Such is the promise of nanotechnology.

. Albert Einstein first proved that each

molecule measures about a nanometer (a billionth

of a meter) in diameter. In 1959, it was Richard P.

Feynman who predicted a technological world

composed of self-replicating molecules whose

purpose would be the production of nano-sized

objects. Almost a hundred years after Einsteins

insight and 40 years after Feynmans initial

proposition, the nanometer scale looms large on the

research agenda. The semiconductor industry is

edging closer to the world of nanotechnology where

components are miniatured to the point of

individual molecules and atoms. A push is well

underway to invent devices that will manufacture

anything at almost no cost, by treating atoms

discretely, like computers treat bits of information.

This would allow automatic construction of

consumer goods without traditional labour, like a

Xerox machine produces unlimited retyping the

original information. Electronics is fuelled by

miniaturization. Working smaller has led to the

tools capable of manipulating individual atoms, just

as the proteins in a potato manipulate the atoms of

soil, water and air to make copies of themselves.

The shotgun marriage of chemistry and

engineering called nanotechnology is ushering in

the era of self-replicating machinery and self-

assembling consumer goods made from cheap raw

atoms


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What is Nanotechnology?

Nanotechnology aims at the design and

creation of functional materials, structures,

devices and systems through direct controlof matter on the nanometer length scale and

exploitation of novel phenomena and properties on this length scale. The length

scale is usually defined as being smaller than

100 nm, depending on the physical and

chemical characteristics of the particularsystem that undergoes quantitative and

qualitative changes when the length scale

boundary is crossed.

Nanotechnology research and development

includes manipulation under control of thenanoscale structures and their integration

into larger material components, systems

and architectures. Within these larger scale

assemblies, the control and construction oftheir structures and components remains at

the nanometer scale. Essential in

nanotechnology is to have a direct control ofmatter either between two nano-objects, or

between a micro (or macro) object and a

nano-object.

The nanoscale is about a thousand timessmaller than micro that is, about 1/80,000

of the diameter of a human hair.

Approximately 3 to 6 atoms can fit insideof a nanometer, depending on the atom.

The prefix nano means ten to the minusninth power, or one billionth. Nanoscale

technologies are the development and use

of devices that have a size of only a fewnanometers. Nanotechnologists

manipulate single molecules and atoms

At nano-scale, different laws come into play.

Properties of traditional materials change and

the behavior of surfaces starts to dominate the

behavior of bulk materials, opening up new

realms. In the electronic domain, the benefit of

working on nano-scale is production of smaller

things. Using nanotubes or other molecular

configurations enables engineers to break

through this barrier in the semiconductor

industry, which is expected to provide even

smaller circuits and even Scale of comparison,

more powerful computers, by working below

the wavelength of light, X-ray; etc. The

ultimate result is circuit elements consisting of

single molecules.


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VARIOUS DEFINITIONS:

Merriam-Webster's (Collegiate Dictionary

definition :) nanotechnologyPronunciation:"na-nO-tek-'n-lo-jE: the art of manipulating materials on an atomic or

molecular scale especially to build microscopic

devices (as robots)

Webopedia's

Definition of nanotechnology a field of science

whose goal is to control\individual atoms and

molecules to create computer chips and other

devices that are thousands of times smaller

than current technologies permit. Current

manufacturing processes use lithography toimprint circuits on semiconductor materials.

While lithography has improved dramaticallyover the last two decades-to the point wheresome manufacturing plants can produce

circuits smaller than one micron (1,000

nanometers)-it still deals with aggregates of

millions of atoms. It is widely believed thatlithography is quickly approaching its physical

limits. To continue reducing the size of

semiconductors, new technologies that juggleindividual atoms will be necessary. This is the

realm nanotechnology. Although researching

this field dates back to Richard P. Feynman'sclassic talk in 1959, the term

Nanotechnology was first coined by K. Eric Drexler in 1986 in thebookEngines of

Creation

After all the simple and understandable

definition of nanotechnology is given as:

Nanotechnology broadly refers to the

manipulation of matter on the atomic and

molecular scales i.e. where the objects of

interests are 0.1-100nm in size.

APPROACHES OF

NANOTECHNOLOGY:

The two fundamentally different approaches to

nanotechnology are graphically termed top-

down and bottom-up. Top down refers to

making nanoscale structures by machining and

etching techniques, whereas bottom-up, or

molecular nanotechnology, applies to building

organic and inorganic structures atom-by-atom,

or molecule-by-molecule. Topbottom or

bottom-up is a measure of the level of

advancement of nanotechnology.

Nanotechnology, as applied today, is still

mainly at what may be considered the more


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primitive bottom-top stage, building upward in

the Molecular scale as shown in the below

figure.

CONCEPTS OF

NANOTECHNOLGY:

There are two concepts commonly associated

with nanotechnology:

Positional Assembly


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Self-Replication

Clearly, we would be happy with any method that

simultaneously achieved the following three

objectives. However, this seems difficult without

using some form of positional assembly (to get the

right molecular parts in the right places) and some

form of self-replication (to keep the costs down).

1. Get essentially every atom in the right place.

2. Make almost any structure consistent with the

laws of physics and chemistry that we can specify

in atomic detail.

3. Have manufacturing costs not greatly exceeding

the cost of the required raw materials and energy.

TOOLS OF

NANOTECHNOLOGY:

The icons of this revolution are scanning probe

microscopesthe scanning tunneling microscope

(STM) and the atomic force microscope (AFM).

Both these machines have the ability to interact with

materials at the molecular level, although this is

limited. They are capable of creating pictures of

individual atoms or moving them from place to

place.

Researches at Cornell University created the worlds smallest guitar carved out of crystalline silicon and worlds smallest car and Taurus of

10nm using an atomic force microscope (AFM).

Drexler has proposed the Assembler, a nanosize

mechanical machine, which could manipulate atoms

precisely. These machines could be told to build

anything. To control these miniature run-abouts,

Drexler has designed the nanocomputer. This is not

an electronic device but one that would work on

rod-logic; a system of criss-crossing

mechanically-operated rods interacting with each

other. These computers would be small, typically

fitting inside a 400-nanometer cube, which is

approximately 1000 times smaller in volume than

one human cell. However, these would be as

powerful as some of todays desktop computers

CARBON NANOTUBES (Key

role in Nano Technology):

In 1991, carbon nanotube was discovered from the

cathode product in carbon-arc discharge method

similar to that used for fullerenes preparation. This

discovery opened a new chapter both in

nanotechnology and in. carbon chemistry


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Based on their unique properties, carbon nanotubesare expected to have variety of applications. A lot of

research has been carried out on synthesis,

characterization,

property measurement and applications of carbonnanotubes and will be continued. The structure of

nano tubes can be seen as shown

.

Various shapes and types of nanotubes (courtesy

www.nanoindustries.com )

REAL-WORLD NANO

EXISTS:In Medicine: Monitoring body state:

Given Imaging, an Israel company, has developed a

pill-size video camera that can travel through the

digestive track and transmit pictures along the way,

providing a less invasive technique to examine the

small intestines. This video camera uses a miniature

CMOS video imaging chip and white LED as a

light source

From left A DNA molecule attached to two electrodes, DNA structure, Future nano robos in medicine, Swan nano

In recent years nano technology is being used in the

field of medicine to an extent, they play a major

role in curing diseases like Cancer, Brain damage,

Harmone deficiency, Infection, hesterostasis,

Telomere loss, Chemical accumulation, DNA

damage etc.


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In Machinery:

Nanotechnology develops minute technology; this

is a model of "nanogears", as small as only a few

atoms wide. As science becomes more sophisticated

it naturally enters the realm of what is arbitrarily

labeled nanotechnology. The essence of

nanotechnology is that as we scale things down they

start to take on extremely novel properties.

Nanoparticles (clusters at nanometer scale), for

example, have very interesting

properties and are proving extremely useful as

catalysts and in other uses. If we ever do make

nanobots, they will not be scaled down versions of

contemporary robots.

Shapes Of Nanogears, Comparison between nanogears and a bug. (Courtesy www.iop.org)

In Space Research:

The stringent fuel constraints for lifting payloads

into earth orbit and beyond and the desire to send

spacecraft away from the sun for extended missions

(where solar power would be greatly diminished)

compel continued reduction in size, weight, and

power consumption of payloads. Nanostructured

materials and devices promise solutions to these

challenges. Nanostructuring is also critical to the

design and manufacture of lightweight, high-

strength, thermally stable materials for aircraft,

rockets, space stations, and planetary/solar

exploratory platforms.

Nano satellite (courtesy www.zyvex.com)
http://www.zyvex.com/http://www.zyvex.com/


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TRANSPORTATION:Nanomaterials and

nanoelectronics will yield lighter, faster, and

safer vehicles and more durable, reliable, and

cost-effective roads, bridges, runways,

pipelines, and rail systems. The replacement of

carbon black in tires by nanometer-scale

particles of inorganic clays and polymers is a

new technology that is leading to the

production of environmentally friendly, wear-

resistant tires

ENVISAGED SUICIDES

Any powerful

technology can be used to do great harm as

well as great good. And Nanotechnology is no

exception to it. The concerns include:

ENVIRONMENTAL

CONTAMINATION

Smart drugs and other nano-devices usedin medical applications could

contaminate the environment

after being expelled from the body.

MUTATION:Smart drugs or other nano-devices

capable of manipulating organic

molecules could interact with cellular

activity in unexpected ways.Titanium dioxide, for example, is

used in sunscreens for its ability toreflect the sun's light and harmful UV

rays. At its nanoscale, it stops

reflecting light and therefore becomes

transparent - and thus morecommercially useful - while

maintaining its ability to reflect

harmful UV rays. Unfortunately,transparency isn't the only change.

Scientists from Oxford have observedthat at nanoscale titanium dioxide canalso pass through the skin and

damage the DNA of cells.

RUNAWAY CONDITIONA smart drug or nano-device capable of

replicating itself could result in a

runaway condition.

WEAPONS

This technology has the potential to be used as

a weapon that would be difficult to control.

Atomic properties could be exploited for

causing destruction

RECOMMENDATIONS:Given the tremendous

potential benefits of nanotechnology, and

the concern that it be developed withsensitivity to potential negative

implications, some recommendations are

quoted below.

Make support for social andeconomic research studies on

nanotechnology a high priority. Build

openness, disclosure, and public participation into the process of

developing nanotechnology research

and development program direction.

Establish a mechanism to inform,

educate, and involve the public

regarding potential impacts ofnanotechnology. The mechanism

should receive feedback from the

nanotechnology community, social

scientists, the private sector, and the

public. Create the knowledge base and

institutional infrastructure to evaluatenanotechnology scientific,

technological, and societal impacts

and implications from short-term (3

to 5 year), medium-term (5 to 20year), and long-term (over 20year)

perspectives.

Educate and train a new generation of

scientists and workers skilled in


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nanoscience and nanotechnology at

all levels with regard to societal

implications.

---SUGGESTIONS FOR PRIVATE

SECTOR

Provide intellectual input and seedfunding of activities aimed atassessing the societal implications of

nanotechnology.

Develop partnerships with academic

institutions and other sectors.

Offer accessibility to social scienceresearchers and provide feedback on

societal implications studies.

---SUGGESTIONS FOR

GOVERNMENT R&DLABORATORIES

Establish interdisciplinary teams for

major grand challenges innanotechnology including socio-

economic perspectives, including

social scientists.

Develop databases for evaluation and

continuously update scenarios for the

future. Establish user facilitiesavailable to industry and academe

that enable integration of basic and

applied research.

---SUGGESTIONS FORGOVERNMENT FUNDING

AGENCIES

Support nanotechnology researchers

and social scientists to study the

societal implications of nanotechnology.

Communicate the resulting activitiesto the public. Provide coordinated

support for long-term basic research

and shorter-term technologicaldevelopments to create thetechnological base and prove the

potential of the new technology.

Provide suggestions for grand

challenges and suggest warning signsof potential risks.

To take full advantage of the

new technology, the entire scientific and

technology community must involve allparticipants, including the general public

creatively envision the future; set broad

goals; and work together to expeditesocietal benefits.

CONCLUSION:

The paper concludes that the

argument is not to relinquish the

technological developments but to keepan eye on the ethical implications so that

we can take the full advantage of it. Man

had already made mistakes over themisuse of nuclear energy, GM products

etc. No more suicidal attempts can be

entertained that can relinquish humansafety. We have experienced to realize

the technological destruction faced bymankind today. No one can be made

responsible for this and unless we findways to safeguard ourselves, we are in

great trouble.


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REFERENCE:

1. ARTICLE NANOTUBE PEAPODS SCIENCE/ TECHNOLOGY, THE HINDU

10 Jan 2002

2. ARTICLE NANOWIRES SCIENCE /TECHNOLOGY, THE HINDU 14 FEB

2002

3. ARTICLE How Nanotechnology Could Help (Miniaturized?) Human Beings

ELECTRONICS FOR YOU MAY 2002

4 J.BR.Interplanet,Nanotechnology: Evolution of the concept

5 The Future Impact of Nanotechnology on textile technology and on textile industry

6 IEEE Instrumentation & Measurement Magazin4. Internet Link -

7 http://www.wtec.org/loyola/nano/NSET.Societal.Implications

8 Internet Link - http://www.phy.mtu.edu/

9 Internet Link http://science.howstuffworks.com/

10 Internet Link http://www.nano.org.uk/

11 Internet Link http://www.spectrum.ieee.org/WEBONLY/resource/

12 Internet Link http://guardianunlimited.com


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