Nanotechnology
324 Pages
English

Nanotechnology

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The theme of this book is Nanotechnology, it’s a technology applied in the grey area between classical mechanics and quantum mechanics. Classical mechanics is the mechanics governing the motion of all the objects we can see with our naked eye. By contrast, quantum mechanics which is the mechanics controlling the motion of things like the electron, the proton, the neutron and the like is completely probabilistic. There is a grey area between these two scales which is neither classical nor quantum. Theoretical physicists call it the mesoscopic system. This is what is called by non-physicists the nanoworld. A nanosystem is therefore something which is sufficiently small that we could not see with our naked eye and not even with an ordinary microscope.

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NANOTECHNOLOGY
Principles and applications


Nanotechnology
Principles and applications



Ahmed A. Moosa
Department of Production Engineering and
Metallurgy
University of Technology
Baghdad –Iraq



2011





A teacher is better than two books
German Proverb


To my wife with
Respect
Understanding
Kindness
Inspiration
Admiration






Acknowledgements

I would like to thank Prof. Dr. Kahtan Al- Khazraji president of
the University of Technology for supporting nanaotechnology
program. Many thanks to Nanotechnology group at the University of
Technology for their help and support. Special thanks to Dr. Bassam
Rasheed, Dr. Abdul- Qader Faisal, Dr. Fadil A. Chyad and Dr. Khalid
A. Sukkar, for their valuable comments. Special thanks to Dr.
Moayad Qudair Director of central Library. Special thanks to Miss
Rana abdul Raheem for reviewing many chapters of this book. Special
thanks to Muna Abdul Husain for reviewing chapter six. Special
thanks to my graduate student Ahmed Flaieh for helping in carbon
nanotube chapter.

Ahmed A. Moosa, Ph.D.
Dept. of Production Eng. and Metallurgy
University of Technology
Baghdad –Iraq, Oct, 2009


Contents

Preface ................................................................................. 15
Chapter One/ General Introduction ............................... 17
1.1. Introduction ........................................................ 19
1.2 What is Nanotechnology ..................................... 21
1.3 Nanomaterials...................................................... 24
1.4 History of Nanotechnology ........ 28
1.5 The Future of nanotechnology ............................ 32
Review Questions ...................................................... 34
References ................................................................. 35

Chapter Two / Atomic Stru cture ...................................... 37
2.1 Introduction ......................................................... 39
2.2 Electrons in Atoms .............................................. 43
2.3 The Periodic Table .............................................. 46
2.4 Atomic Bonds ...................................................... 49
2.5 Bonding Forces and Energies.............................. 49
2.6 Primary Bonds ...............................52
2.6.1 Ionic Bonding ............................................ 52
2.6.2 Covalent Bonding ............ 54
2.6.3 Metallic Bonding ............. 56
2.7 Secondary Bonds................................................ 57
2.7.1 Van der Waals bonding ............................. 58
2.7.2 Hydrogen bonds......................................... 60
Review Questions............................. 61
References ................................................................. 63

Chapter Three/ The Structure of Crystalline Solids ..... 65
3.1 Introduction ......................................................... 67
3.2 Crystal Structure.................................................. 69
3.3 Cubic Crystal Structures ...................................... 71
9
3.3.1 The Simple Cubic Crystal Structure
(SC) .................................................................... 74
3.3.2 Body -Centered Cubic Crystals (BCC) ..... 75
3.3.3 Face Centered Cubic (FCC)....................... 76
3.4 Hexagonal Close Packed Structure (HPC)........ 78
3.5 Density Computations ......................................... 79
3.6 Vectors ................................................................. 82
3.7 Fundamental Definitions ..................................... 83
3.8 Crystallographic Directions................................. 86
3.9 Miller Indices ...................................................... 88
3.10 Introduction to X-Ray ....................................... 90
3.11 X-Ray Diffraction.......................... 93
Review Questions...................................................... 96
References ................................................................. 100

Chapter Four/ Quantum Mechanics .............................. 101
4.1 History of Quantum Mechanics .......................... 103
4.2 Einstein's Light Quanta Hypothesis .................... 104
4.3 Bohr Atomic Model............................................. 105
4.4 The Pauli Exclusion Principle ............................. 106
4.5 Photons Interaction with matters.............107
4.5.1 Photoelectric Effect ................................... 107
4.5.2 Compton Effects ........................................ 110
4.6 Schrödinger's Equation ........................................ 113
4.7 Free Particle......................................................... 114
4.8 Particle in a One Dimension Box ...................... 115
4.9 Density of States.................................................. 118
4.10 Tunneling........................................................... 124
Review Questions...................................................... 128
References ............................................. 129

Chapter Five/ Synthesis of Nanomaterials ...................... 131
5.1 Introduction ........................................................ 133
5.1.1 Top-down Approach .................................. 133
5.1.2 Bottom- up Approach ................................ 134
5.2 Synthesis of Nanoparticles ................................. 136
10
5.3Mechanical Methods ............................................ 137
5.4 Physical Vapor Deposition.................................. 138
5.4.1 Evaporation ...................... 139
5.4.2 Sputtering .................................................. 144
5.4.3 Pulsed Laser Deposition ............................ 148
5.5 Molecular Beam Epitaxy....................
5.6 Chemical Vapor............................... 149
5.6.1 Low Pressure Chemical Vapor
Deposition........................................................... 151
5.6.2 Plasma-Enhanced CVD ............................. 152
5.7 Sol-Gel Process ................................................... 154
Review Questions...................................................... 156
References ........................................ 157

Chapter six / Analysis Techniques .................................. 159
6.1 Abbreviation........................................................ 161
6.2 Electron Microscopes .......................................... 162
6.3 Electron interactions with Matters ..................... 166
6.3.1 Bulk Specimen Interactions....................... 166
6.3.2 Backscattered Electrons............................. 168
6.3.3 Secondary Electrons .................................. 169
6.3.4 Auger Electrons ........................
6.3.5 X-rays ........................................................ 170
6.4 Scanning Electron Microscope (SEM)................ 171
6.4.1 The Electron Source .................................. 175
6.4.2 Beam's Path through the Column .............. 176
6.5 Specimen Preparation.......................................... 177
6.6 Thin Specimen Interactions................................. 177
6.6.1 Unscattered Electrons ..............
6.6.2 Elastically Scattered electrons ................... 178
6.6.3 Inelastically Scattered Electrons................ 178
6.7 Transmission Electron Microscope..................... 179
6.8 Scanning probe microscopy ................................ 182
6.9 Scanning Tunneling microscope (STM) ............. 183
6.9.1 Tunneling................................................... 187
6.9.2 Applications of STM ................................. 191
11
6.10 Atomic Force Microscope................................. 192
6.10.1 AFM Tips................................................. 195
6.10.2 AFM Cantilever ....................................... 196
6.10.3 AFM Mode of Operation......................... 200
6.10.4 Applications of AFM............................... 202
6.11 Nanoindentaion Hardness Testing .................... 203
6.12 Photoelectron Spectroscopy ............................. 207
6.13 Near-field Scanning Optical Microscopy
(SNOM) .................................................................... 209
References ................................................................. 212

Chapter Seven / Carbon Nanotubes ................................. 217
7.1 Introduction ......................................................... 219
7.2 Carbon nanotubes................................................ 223
7.3 Properties of Carbon Nanotubes......................... 229
7.3.1 Chemical Reactivity................................... 230
7.3.2 Electrical Conductivity .............................. 231
7.3.3 Optical Activity ......................................... 231
7.3.4 Mechanical Strength ................
7.3.5 Thermal Properties..................................... 232
7.3.6 Toxicity...................................................... 233
7. 4 Synthesis of Carbon Nanotubes ......................... 233
7.4.1 Laser Ablation Method .............................. 235
7.4.2 Chemical Vapor Deposition (CVD) .......... 236
7.4.3 Arc Discharge ............................................ 238
7.5 Applications of CNT ........................................... 240
7.5.1 Energy storage
7.5.2 Electrochemical Supercapacitors............... 243
7.5.3 Field emitting devices................................ 244
7.5.4 Chemical Sensors ....................................... 245
7.5.5 Composite Materials.................
7.5.6 Fibers and Fabrics...................................... 247
References ................................................................. 248

Chapter Eight / Applications of Nanotechnology ........... 253
8.1 Introduction ......................................................... 255
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8.2 Nanotechnology and Medicine............................ 258
8.2.1 Drug-Delivery Techniques ....................... 263
8.2.2 Gold Nanoshells ......................................... 264
8.2.3 Therapeutic Nanoparticles......................... 265
8.2.4 Nanoparticles for Biomedical Imaging and
Diagnostics .............................................. 267
8.2.5 Nanotech Sensor Detects Toxins in Living
Cells............................................................ 268
8.2.6 Anti-Malarial Drug .................................... 269
8.3 Application of Nanotechnology in Filtration ...... 269
8.3.1 Nanofiltration (NF).................................... 270
8.3.2 Applications of Carbon Nanotube in
WaterFiltration .................................................. 275
8.3.3 Ultrafiltration (UF) ................................. 277
8.4 Application of Nanotechnology in
Environment ....................................................... 278
8.5 Application of Nanotechnology in Energy .......... 279
8.6 Applis of Nanoparticles............................. 281
8.6.1 Fullerenes, Buckyballs and Carbon
Tubes ................................................................. 282
8.6.2 Liposomes.................................................. 284
8.6.3 Nanoshells .......
6.6.4 Dendrimers ................................................ 285
8.6.5 Quantum Dots............................................ 285
8.6.6 Superparamagnetic Nanoparticles........................
References ................................................................. 292
Glossary .................. 295






13
14
Preface
Nanotechnology is about new ways of making things.
Nanotechnology is a technology applied in the grey area between
classical mechanics and quantum mechanics. Classical mechanics is
the mechanics governing the motion of all the objects we can see with
our naked eye. By contrast, quantum mechanics which is the
mechanics controlling the motion of things like the electron, the
proton, the neutron and the like is completely probabilistic. There is
a grey area between these two scales which is neither classical nor
quantum. Theoretical physicists call it the mesoscopic system. This is
what is called by non-physicists the nanoworld. A nanosystem is
therefore something which is sufficiently small that we could not see
with our naked eye and not even with an ordinary microscope.
Nanotechnology started with the invention of scanning tunneling
microscope by Bennig and Rohrer in 1981 and further development.
Nanotechnology is a collective term for a set of technologies,
techniques and processes – effectively a new way of thinking - rather
than a specific area of science or engineering. Few industries will
escape the influence of nanotechnology. Faster computers, advanced
pharmaceuticals, controlled drug delivery, biocompatible materials,
nerve and tissue repair, surface coatings, better skin care and
protection, catalysts, sensors, telecommunications, magnetic materials
and devices - these are just some areas where nanotechnology will
have a major impact.
15
Because of the rapid pace of development of nanotechnology
subject, and its interdisciplinary nature, truly comprehensive coverage
does not seem feasible. The topics presented in this book were chosen
based on the maturity of understanding of the subjects, their potential
for applications, or the number of already existing applications.
An introduction to the subject of nanotechnology was presented
in Chapter one. The atomic structure and the Structure of Crystalline
Solids were presented in chapter two and three. Quantum mechanics
was presented in chapter four. Synthesis of nonmaterials was
presented in Chapter five.
An important impetus that caused nanotechnology to advance so
rapidly has been the development of instrumentation such as the
scanning tunneling microscope that allows the visualization of the
surfaces of nanometer sized materials. Hence Chapter six presents
descriptions of important instrumentation systems. The remaining
chapters cover various aspects of the field. Carbon nanotubes were
presented in Chapter seven. Application of nanotechnology was
presented in chapter eight.
This book can be covered as a one semester graduate course or
as one year undergraduate course. Many references were given in this
book together with glossary of nano terms.
Ahmed A. Moosa, Ph.D.
Dept. of Production Eng. and Metallurgy
University of Technology
Baghdad –Iraq, Oct, 2009
16






Chapter One
General Introduction
17
18
Chapter One
General Introduction
“Just as the British Industrial Revolution knocked
handspinners and handweavers out of business, nanotechnology will
disrupt a slew of multi - billion dollar companies and industries.”
– Lux Research, Inc. The Nanotech Report 2004
1.1. Introduction
The subject of nanotechnology is the science of the small.
Nano is Greek for dwarf, and nanoscience deals with the study of
molecular and atomic particles, a world that is measured in
-9nanometers (billionths of a meter or 10 ). A nanometer is one
-9billionth of a meter (10 ). That’s very small. At this scale, you
are talking about the size of atoms and molecules. To create a
visual image of a nanometer, the width of your nail on this finger
is about 10 million nanometers across. To get a sense of some
other nano-scaled objects, the diameter of a human hair is
between 50,000 and 100,000 nanometers. A head of a pin is
about a million nanometers wide and it would take about 10
hydrogen atoms end-to-end to span the length of one nanometer.
The length of red blood cell is approximately 7,000 nm wide and
a water molecule is almost 0.3nm across. Figure 1.1 and Table
1.1 show the dimensions of different items.
19
Nanotechnology is the ability to observe measure,
manipulate, assemble, control and manufacture matter at the
nanometer scale. People are interested in the nanoscale because
it is at this scale that the properties of materials can be very
different from those at a larger scale. Nanoscience is a
convergence of physics, chemistry, materials science and
biology, which deals with the manipulation of materials at
atomic, molecular and macromolecular scales; nanotechnology is
an emerging engineering discipline that applies methods from
nanoscience to create products.


Figure 1.1
(a) Less than a nanometer, individual atoms is up to a few angstroms,
or up to a few tenths of a nanometer, in diameter.
(b) Nanometer, ten shoulder-to-shoulder hydrogen atoms. DNA
molecules are about 2.5 nanometers wide.
(c) A thousands of nanometers, biological cells, like these red blood
cells, have diameters in the range of thousands of nanometers.
20
1.2 What is Nanotechnology
Nanotechnology has become a topic of widespread
discussion amongst researchers, in the media, among the
investment community and elsewhere. Nanotechnology is about
new ways of making things. It promises more for less: smaller,
cheaper, lighter and faster devices with greater functionality,
using fewer raw materials and consuming less energy.
Nanotechnology and nanoscience are concerned with materials
science and its application at, or around, the nanometre scale (1
billionth of a meter). Manufacturing can reach the nano scale
either from the top

Table 1.1 The dimension of some different items
Items Dimensions (nm)
Width of an Atom 1
The Width Across a DNA Molecule 2
Protein 5 – 50
Virus 75 – 100
The Width of a Wire in a Computer 100 of a Dust Particle 800
Bacteria 1,000 – 10,000
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White Blood Cell 10,000
The Width of a Hair 100,000 Across the Nail of a Finger 10,000,000

down, by ‘machining’ to ever smaller dimensions, or from
the bottom up, by exploiting the ability of molecules and
biological systems to ‘self- assemble’ tiny structures . In short,
nanotechnology is the ability to build micro and macro materials
and products with atomic precision. The promise and essence of
the nanoscale science and technology is based on the
demonstrated fact that materials at the nanoscale have properties
(i.e. chemical, electrical, magnetic, mechanical and optical) quite
different from the bulk materials. For instance, opaque
substances become transparent (copper); inert materials become
catalysts (platinum); stable materials turn combustible
(aluminum); solids turn into liquids at room temperature (gold);
insulators become conductors (silicon). A material such as gold,
which is chemically inert at normal scales, can serve as a potent
chemical catalyst at nanoscales. Composites made from particles
of nano-size ceramics or metals smaller than 100 nanometers can
suddenly become much stronger than predicted by existing
materials-science models. For example, metals with a so-called
grain size of around 10 nanometers are as much as seven times
harder and tougher than their ordinary counterparts with grain
22
sizes in the hundreds of nanometers. The causes of these drastic
changes stem from the weird world of quantum physics. At
nanoscale various physical phenomena will be changed: gravity
would become less important, surface tension and Van der Waals
attraction would become more important, etc. Much of the
fascination with nanotechnology stems from these unique
quantum and surface phenomena that matter exhibits at the
nanoscale.
At the most basic technical level, Molecular
Nanotechnology (MNT) is building, with intent and design,
molecule by molecule. MNT represents the state of the art in
advances in biology, chemistry, physics, engineering, computer
science and mathematics. The major research objectives in MNT
are the design, modeling, and fabrication of molecular machines
and molecular devices. The emergence of MNT - both infant and
mature - has numerous social, legal, cultural, ethical, religious,
philosophical and political implications. Dr K. Eric Drexel
expected that nanotechnology will involve the following items:
1- End of famine and starvation
2- Superior education for every child on Earth.
3- Reintroduction of many extinct plants and animals.
4- Terraforming Earth and the Solar System.
5- Safe and affordable space travel.
6- PC's billions of times faster then today.
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7- Virtual end to illness, aging, and death.
8- No more pollution and automatic cleanup of existing
pollution.
Many materials, once they are individually reduced below
100 nanometers, begin displaying a set of unique characteristics
based on quantum mechanical forces that are exhibited at the
level. Due to these quantum mechanical effects, materials may
become more conducting, be able to transfer heat better, or have
modified mechanical properties. Imagine a world in which
microscopic procreating robots are sent into the human body
with the mission of detecting cancer cells, disassembling them,
and sending them out into the bloodstream as waste products.
In some senses, nanoscience and nanotechnologies are not
new. Chemists have been making polymers, which are large
molecules made up of nanoscale subunits, for many decades and
nanotechnologies have been used to create the tiny features on
computer chips for the past 20 years. However, developments in
the tools that now allow atoms and molecules to be examined
and probed with great precision have enabled the expansion and
development of nanoscience and nanotechnologies.
1.3 Nanomaterials
Nanomaterials are defined as those which have structured
components with at least one dimension less than 100nm. In
24
quantum mechanics the particle confinement ( Figure 1.2 ) can
be classified as: Materials that are confined in one dimension i.e
has a nanoscale one dimension (freedom in 2 dimensions) like
thin film is called two dimensions (2D) quantum well. Materials
that are confined in two dimensions i.e have a two nanoscale
dimensions (freedom in one dimension or 1D) is called one
dimension (1D) nanowires wire. Materials that are confined in
three dimensions i.e has a three nanoscale dimensions (no
freedom in any direction or zero dimension) is called zero
dimension quantum dot or nanoparticles. For example
precipitates, colloids and quantum dots (tiny particles of
semiconductor materials). Nanocrystalline materials, made up of
nanometre-sized grains, also fall into this category.
Two principal factors cause the properties of nanomaterials
to differ significantly from other materials: increased relative
surface area, and quantum effects. These factors can change or
enhance properties such as reactivity, strength and electrical
characteristics. As a particle decreases in size, a greater
proportion of atoms are found at the surface compared to those
inside. For example, a particle of size 30 nm has 5% of its atoms
on its surface, at 10 nm has 20% of its atoms, and at 3 nm
has50% of its atoms. Thus, nanoparticles have a much greater
surface area per unit mass compared with larger particles. As
growth and catalytic chemical reactions occur at surfaces, this
25
means that a given mass of material in nanoparticulate form will
be much more reactive than the same mass of material made up
of larger particles.
To understand the effect of particle size on surface area,
consider a silver coin with a 26.96 grams of silver, and has a
diameter of about 40 mm, and has a total surface area of
2approximately 27.70 cm . If the same amount of coin silver
were divided into tiny particles – say 1 nanometer in diameter –
the total surface area of those particles would.

Figure 1.2 Curvilinear and (b) rectangular nanostructures.
be 11,400 square meters. Thus, the surface area of those
particles is 4.115 million times greater than the surface area of
the silver coin.
26
For cube with one side equal to 3 mm, the ratio of its
surface area/ volume is 2. If the side of the cube is reduced to 1
cm then the ratio of surface area/ volume is 6 as shown in Table
1.2.
Table 1.2 Surface Areas to Volume Ratio of Cubic Box.
Volume of
Length of Side of Surface Area of Ratio of
Cube (V)
2Cube (mm) Cube (A) (mm ) A/V
3(mm )
3 27 54 2
2 8 24 3
1 1 6 6

The quantum effects can begin to dominate the properties
of matter as size is reduced to the nanoscale. These can affect the
optical, electrical and magnetic behavior of materials,
particularly as the structure or particle size approaches the
smaller end of the nanoscale. Materials that exploit these effects
include quantum dots, and quantum well lasers for
optoelectronics.
For other materials such as crystalline solids, as the size of
their structural components decreases, there is much greater
interface area within the material; this can greatly affect both
mechanical and electrical properties. For example, most metals
27
are made up of small crystalline grains; the boundaries between
the grain slow down or arrest the propagation of defects when
the material is stressed, thus giving it strength. If these grains can
be made very small, or even nanoscale in size, the interface area
within the material greatly increases, which enhances its
strength. For example, nanocrystalline nickel is as strong as
hardened steel. Understanding surfaces and interfaces is a key
challenge for those working on nanomaterials, and one where
new imaging and analysis instruments are vital.
1.4 History of Nanotechnology
1900: Rutherford: discovery of atomic nucleus.
1959: Feynman gives after-dinner talk describing molecular
machines building with atomic precision "There is plenty of
room at the bottom".
1969: Invention of Surface Forces Apparatus (SFA).
1974: Taniguchi uses term "nano-technology".
1977: Drexler originates molecular nanotechnology concepts at
MIT.
1981: Invention of the Scanning Tunneling Microscope (STM)
by Rohrer and Binnig at IBM Zurich (Nobel Prize 1986) .
1985: Fullerene " buckyballs" discovered at Rice University
(Nobel prize awarded in 1996).
1986: Invention of Atomic Force Microscope (AFM) by Binnig,
28
Gerber, and Quate, measurement of 10-12 N forces.
First book published by Eric Drexler "Engines of Creation".
1989: IBM logo spelled in individual atoms.
1990: First nanotechnology journal.
1991: Carbon nanotube was discovered.
1992: First single molecule force spectroscopy experiments.
1993: First Feynman Prize in Nanotechnology awarded
"Engines of Creation" book given to Rice administration,
stimulating first university nanotech center.
1994: Nanosystems textbook used in first university course
1995: First industry analysis of military applications.
1996: $250,000 Feynman Grand Prize announced
1997: First design of nanorobotic system.
2000: President Clinton announces U.S. National
Nanotechnology Initiative. .
2004: Journals: Nanotechnology, Nano Letters, Journal of
Nanoscience and Nanotechnology, IEEE Transactions on
Nanotechnology.
The first use of the distinguishing concepts in
'nanotechnology' was done by the Nobel Prize-winning physicist
Richard Feynman in his talk "There's Plenty of Room at the
Bottom " at an American Physical Society meeting at Caltech on
December 29, 1959 . Feynman described a process by which
the ability to manipulate individual atoms and molecules might
29
be developed, using one set of precise tools to build and operate
another proportionally smaller set, so on down to the needed
scale.. "There's no question that there is enough room on the
head of a pin to put the entire encyclopedia Britanica" he said.
Feynman stated in his lecture that the entire encyclopedia of
Britannica could be put on the tip of a needle and, in principle,
there is no law preventing such an undertaking. Feynman
proposed how to create macro-scale products built from
individual molecules - a "bottom-up manufacturing" technique,
as opposed to the usual technique of cutting away material until
you have a completed component or product - "top-down
manufacturing".
The term "nanotechnology" was defined by Tokyo Science
University Professor Norio Taniguchi in a 1974 as :
"'Nanotechnology' mainly consists of the processing of, separation,
consolidation, and deformation of materials by one atom or by
one molecule."
The next milestone comes in 1981, when MIT graduate
student K. Eric Drexler, inspired by Feynman, published an
article called " Protein Design as Pathway to Molecular
Manufacturing." This is followed by Drexler's definitive 1986
book, "Engines of Creation".
Nanotechnology and nanoscience got started in the early
1980s with two major developments; the birth of cluster science
30
and the invention of the scanning tunneling microscope (STM).
The scanning Tunneling Microscope (STM) was invented in
1982 by G. Binning and H. Rohrer and the inventers were
awarded the Nobel Prize for physics in 1986. In Scanning
Tunneling Microscope (STM), the phenomenon like of electron
tunneling is used to obtain an image of the topography of the
surface. These developments led to the discovery of fullerenes
in 1986 and carbon nanotubes a few years later. In another
development, the synthesis and properties of semiconductor
nanocrystals was studied. This led to a fast increasing number of
metal oxide nanoparticles of quantum dots. The atomic force
microscope was invented five years after the STM was invented.
The AFM uses atomic force to see the atoms .
To initiate molecular nanotechnology (MNT) revolution
would require an "assembler". An assembler is a mechanism for
guiding chemical reactions by positioning reactive molecular
tools by moving its tool-holding end in three dimensions like an
industrial robot arm. Nanobot, then, may be an assembler or
some other sort of nanoscale robotic mechanism.
Molecular manufacturing is a process of construction based
on atom-by-atom control of product structures, which may use
assemblers (or more specialized mechanisms) to guide a
sequence of chemical reactions. If an assembler were packaged
together with all of the machinery needed to power it, direct it,
31
and prepare its reactive molecular tools, and with all of the
instructions needed to guide the construction of another identical
microscopic package, it would then form the heart of (one kind
of) nanoreplicator.
The arrival of MNT would revolutionize wide sectors of
human activity, including manufacturing, medicine, scientific
research, communication, computing, and warfare. When
fullblown molecular nanotechnology will arrive is currently
unknown, but many experts foresee its arrival between 2010 and
2020.
1.5 The Future of Nanotechnology
The potential market for nanotechnology for 2015 ranges
from tens of billions to trillions of dollars. Japan recently
committed itself to a central government spend of some £400
million, for the fiscal year 2002. In the USA, the federal budget
for 2002 includes $604 million for research and development in
nanotechnology. Government spending in the UK on
nanotechnology R&D in 2002 is about 45 million $ a year. The
National Science Foundation predicts that the global marketplace
for goods and services using nanotechnologies will be worth a
trillion dollars by 2015. In the same year, career opportunities in
this fast-paced technology will require 2–5 million semiskilled
and skilled employees worldwide. Nanotechnology has the
32
potential to affect everything from the clothes we wear, to the
energy we use, to the way we detect and treat cancer and other
diseases.
In order to allow optimal commercialization of
nanotechnology based products, the important enablers in this
vast field should be recognized early on. A useful way to
organize this area is by defining the following four
competencies:
1. Nanosynthesis: making nanoscale building blocks including
nanoparticles, nanotubes, and nanostructures.
2. Nanofabrication and nanoprocessing: manipulating and
processing nanoscale building blocks for a desired purpose.
3. Nanoincorporation: incorporating nanoscale building blocks
into final product forms including polymer composites,
electronic materials, and biomedical devices.
4. Nanocharacterization: measuring and characterizing the
basic properties of nanoscale building blocks or final
product forms as well as in manufacturing processes.
Important Terms and Concepts
AFM Nanofabrication Quantum
we ll
Bottom-up NanometerSTM
Buckyballs Nanoscience Top-down
Carbon nanotube Nanotechnology
MNT Quantum dot
33
Review Questions
1.1 What is nanotechnology and how it is going to affect our
lives?
1.2 From where does the word ‘nano’ originate?
1.3 Briefly explain the history of Nanotechnology.
1.4 What is the drawbacks/disadvantages of nanotechnology?
1.5 What is the latest developments in the field of
nanotechnology?
1.6 What is nanoscienec ?
1.7 Give few examples of significant applications of
nanotechnology.
1.8 Who invented carbon nanotubes?
1.9 Explain how nanotechnology will revolutionize the world.
1.10 Explain the difference between bottom-up and top-down
techniques.

34

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