CHAPTER 1 INTRODUCTION
1
INTRODUCTION
Objective: The purpose of this report is to explore about Nanotechnology an emerging field of science and bring to the knowledge the various advancements achieved in this field. The report provide a thorough knowledge about works of various scientists in the field of nanotechnology and what benefits this field can bring into human lives.
Limitations:
1. Since nanotechnology is a huge field, time constraints proved to be a limitation in acquiring greater details about the field. 2. Inability to reach and speak to various scientists involved with studies and exploration of the field limited the scope of study. 3. Practical viewing of nanotechnological material development was also a limitation factor since the research institutes are located far away in the country.
This report is made for all interested readers without aiming particularly at science savvy readers. Nanotechnology is a vast and very technical subject to explain thus the focus behind this project has been to make it as simple as possible. The report explains what nanotechnology is and also various materials invented through it which are not very well known to an ordinary man as yet. Further the report also explains about the possibilities of generation of extremely minute nanobots which can be infused in a human bodies to achieve various medical aids and powerful treatments.
Nanotechnology (sometimes shortened to "nanotech") is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres. Quantum mechanical effects are important at this quantum-realm scale. Nanotechnology is very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to investigating whether we can directly control matter on the atomic scale. Nanotechnology entails the application of fields of science as diverse as surface science, organic chemistry, molecular biology, semiconductor physics, microfabrication, etc.
2
The Nanoscale: Ordinary objects are absolutely huge measured on what scientists call the nanoscale. Various objects length in nanometers is as computed below:
? ? ? ? ? ? ? ? ? ? ?
Atom: ~0.1 nanometers. Atoms in a molecule: ~0.15 nanometers apart. DNA double-helix: ~2 nanometers in diameter. Typical protein: ~10 nanometers long. Computer transistor (switch): ~100-200 nanometers wide. Typical bacteria: ~200 nanometers long. Human hair: ~10,000 nanometers in diameter. One piece of paper: ~100,000 nanometers thick. Girl 1.2 m (4ft) tall: ~1200 million nanometers tall. Man 2m (6.5 ft) tall ~ 2000 million nanometers tall. Empire State Building: 381m (1250 ft) tall: ~381,000 million nanometers tall.
This shows that how minute is a nanoscale as compared to an ordinary meter scale.
3
CHAPTER 2 BACKGROUND OF NANOTECHNOLOGY
4
Background of Nanotechnology
The brilliant American physicist Richard Feynman (1918–1988) is widely credited with kickstarting modern interest in nanotechnology. In 1959, in a famous after-dinner speech called "There's plenty of room at the bottom," the ever-imaginative Feynman speculated about an incredibly tiny world where people could use tiny tools to rearrange atoms and molecules. By 1974, Japanese engineering professor Norio Taniguchi had named this field
"nanotechnology." Nanotechnology really took off in the 1980s. That was when nanotech-evangelist Dr K. Eric Drexler first published his book Engines of Creation: The Coming Era of Nanotechnology. It was also the decade when microscopes appeared that were capable of manipulating atoms and molecules on the nanoscale. In 1991, carbon nanotubes were discovered by another Japanese scientist, Sumio Iijima, opening up huge interest in new engineering applications. The graphite in pencils is a soft form of carbon. In 1998, some American scientists built themselves another kind of pencil from a carbon nanotube and then used it, under a microscope, to write the words "NANOTUBE NANOPENCIL" with letters only 10 nanometers across. Stunts like this captured the public imagination, but they also led to nanotechnology being recognized and taken seriously at the highest political levels. In 2000, President Bill Clinton sealed the importance of nanotechnology when he launched a major US government program called the National Nanotechnology Initiative (NNI), designed to fund groundbreaking research and inspire public interest.
5
CHAPTER 3 NANOSCIENCE
6
Nanoscience
Our lives have some meaning on a scale of meters, but it's impossible to think about ordinary, everyday existence on a scale 1000 times smaller than even a fly's eye. We can't really think about problems like AIDS, world poverty, or global warming, because they lose all meaning on the nanoscale. Yet the nanoscale—the world where atoms, molecules (atoms joined together), proteins, and cells rule —is a place where science and technology gain an entirely new meaning. By zooming in to the nanoscale, we can figure out how some of the puzzling things in our world actually work by seeing how atoms and molecules make them happen. The nanoscale is good because it lets us do nanoscience: it helps us understand why things happen by studying them at the smallest possible scale. Once we understand nanoscience, we can do some nanotechnology: we can put the science into action to help solve our problems. That's what the word "technology" means and it's how technology (applied science) differs from pure science, which is about studying things for their own sake.
Nanoscale importance: It turns out there are some very interesting things about the nanoscale. Lots of substances behave very differently in the world of atoms and molecules. For example, the metal copper is transparent on the nanoscale while gold, which is normally unreactive, becomes chemically very active. Carbon, which is quite soft in its normally occurring form (graphite), becomes incredibly hard when it's tightly packed into a nanoscopic arrangement called a nanotube. In other words, materials can have different physical properties on the nanoscale even though they're still the same materials. On the nanoscale, it's easier for atoms and molecules to move around and between one another, so the chemical properties of materials can also be different. Nanoparticles have much more surface area exposed to other nanoparticles, so they are very good as catalysts (substances that speed up chemical reactions). One reason for these differences is that different factors become important on the nanoscale. In our everyday world, gravity is the most important force we encounter: it dominates everything around us, from the way our hair hangs down around our head to the way Earth has different seasons at different times of year. But on the nanoscale, gravity is much less 7
important than the electromagnetic forces between atoms and molecules. Factors like thermal vibrations (the way atoms and molecules store heat by vibrating) also become extremely significant. In short, science rules get altered when we talk for objects at nonoscale. Methods to work on a nanoscale: Scientists have developed electron microscopes that allow us to "see" things on the nanoscale and also manipulate them. They're called atomic force microscopes (AFMs), scanning probe microscopes (SPMs), and scanning tunneling microscopes (STMs).
Figure 3.1: The eight tiny probe tips on the Atomic Force Microscope (AFM) built into NASA's Phoenix Mars Lander. The tip enlarged in the circle is the same size as a smoke particle at its base (2 microns).
The basic idea of an electron microscope is to use a beam of electrons to see things that are too small to see using a beam of light. A nanoscopic microscope uses electronic and quantum effects to see things that are even smaller. It also has a tiny probe on it that can be used to shift atoms and molecules around and rearrange them like tiny building blocks. In 1989, IBM researcher Don Eigler used a microscope like this to spell out the word I-B-M by moving individual atoms into position. Other scientists have used similar techniques to draw pictures of nanoscopic guitars, books, and all kinds of other things. These are mostly frivolous exercises, designed to wow people with nanopower. But they also have important practical 8
applications. There are lots of other ways of working with nanotechnology, including molecular beam epitaxy, which is a way of growing single crystals one layer of atoms at a time.
9
CHAPTER 4 APPLICATIONS OF NANOTECHNOLOGY
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Applications of Nanotechnology
Most of nanotechnology's benefits will happen decades in the future, but it's already helping to improve our world in many different ways. We tend to think of nanotechnology as something new and alien, perhaps because the word "technology" implies artificial and human-made, but life itself is an example of nanotechnology: proteins, bacteria, viruses, and cells all work on the nanoscopic scale. Nanomaterials:
Figure 4.1: Making an electric circuit with carbon nanotubes. A carbon nanotube (shown here in light blue at the top) is connected to an electricity supply using aluminium (shown in dark blue at the bottom).
There are lot many nanotechnologically devised materials produced which we even might be using without knowing the technology behind. We might be wearing nanotechnology pants, walking on a nanotechnology rug, sleeping on nanotechnology sheets, or hauling nanotechnology luggage to the airport. All these products are made from fabrics coated with "nanowhiskers." These tiny surface fibers are so small that dirt cannot penetrate into them, which means the deeper layers of material stay clean. Some brands of sunscreens use nanotechnology in a similar way. They coat our skin with a layer of
nanoscopic titanium dioxide or zinc oxide that blocks out the Sun's harmful ultraviolet rays. Nano-coatings are also appearing on scratch-resistant car bumpers, anti-slip steps on vans and buses, corrosion resistant paints, and wound dressings.
11
Carbon nanotubes are among the most exciting of nanomaterials. These rod-shaped carbon molecules are roughly one nanometer across. Although they're hollow, their densely packed structure makes them incredibly strong and they can be grown into fibers of virtually any length. NASA scientists have recently proposed carbon nanotubes could be used to make a gigantic elevator stretching all the way from Earth into space. Equipment and people could be shuttled slowly up and down this "carbon ladder to the stars," saving the need for expensive rocket flights. Nanochips:
Figure 4.2: a single molecule of the semiconductor material cadmium sulfide
One form of nanotechnology we all use is microelectronics. The "micro" part of that word suggests computer chips work on the microscopic scal. But since terms like "microchip" were coined in the 1970s, electronic engineers have found ways of packing even more transistor switches into circuits to make computers that are smaller, faster, and cheaper than ever before. This constant increase in computing power goes by the name of Moore's Law, and nanotechnology will ensure it continues well into the future. Everyday transistors in the early 21st-century are just 100-200 nanometers wide, but cutting-edge experiments are already developing much smaller devices. In 1998, scientists made a transistor from a single carbon nanotube.
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And it's not just the chips inside computers that use nanotechnology. The displays on everything from iPods and cellphones to laptops and flatscreen TVs are shifting to organic light-emitting diodes (OLEDs), made from plastic films built on the nanoscale. Nanomachines:
Figure 4.3: The world's smallest chain drive. An example of a nanomachine, this nanotechnology "bike chain" and gear system was developed by scientists at Sandia National Laboratory
Figure 4.4: These nanogears were made by attaching benzene
molecules (outer white blobs) to the outsides of carbon nanotubes (inner gray rings)
13
One of the most exciting areas of nanotechnology is the possibility of building incredibly small machines—things like gears, switches, pumps, or engines—from individual atoms. Nanomachines could be made into nanorobots (sometimes called "nanobots") that could be injected into our bodies to carry out repairs or sent into hazardous or dangerous environments, perhaps to clean up disused nuclear power plants. As is so often the case, nature leads humans here. Scientists have already found numerous examples of nanomachines in the natural world. For example, a common bacteria called E.coli can build itself a little nanotechnology tail that it whips around like a kind of propeller to move it closer to food. Making nanomachines is also known as molecular manufacturing and molecular nanotechnology (MNT).
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CHAPTER 5 CURRENT RESEARCH
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Current Research
The current research approaches can be classified as follows: 1. Top-down approaches: These seek to create smaller devices by using larger ones to direct their assembly. Many technologies that descended from conventional solid-state silicon methods for fabricating microprocessors are now capable of creating features smaller than 100 nm, falling under the definition of nanotechnology. Giant magnetoresistance-based hard drives already on the market fit this description, as do atomic layer deposition (ALD) techniques. Peter Grünberg and Albert Fert received the Nobel Prize in Physics in 2007 for their discovery of Giant magnetoresistance and contributions to the field of spintronics. Solid-state techniques can also be used to create devices known as nanoelectromechanical systems or NEMS, which are related to microelectromechanical systems or MEMS. Focused ion beams can directly remove material, or even deposit material when suitable pre-cursor gasses are applied at the same time. For example, this technique is used routinely to create sub-100 nm sections of material for analysis in Transmission electron microscopy. Atomic force microscope tips can be used as a nanoscale "write head" to deposit a resist, which is then followed by an etching process to remove material in a topdown method. 2. Functional approaches: These seek to develop components of a desired functionality without regard to how they might be assembled. Molecular scale electronics seeks to develop molecules with useful electronic properties. These could then be used as single-molecule components in a nanoelectronic device. Synthetic chemical methods can also be used to create synthetic molecular motors, such as in a so-called nanocar. 3. Biomimetic approaches: Bionics or biomimicry seeks to apply biological methods and systems found in nature, to the study and design of engineering systems and modern technology. Biomineralization is one example of the systems studied. Bionanotechnology is the use of biomolecules for 16
applications in nanotechnology, including use of viruses. Nanocellulose is a potential bulk-scale application. 4. Speculative: These subfields seek to anticipate what inventions nanotechnology might yield, or attempt to propose an agenda along which inquiry might progress. These often take a big-picture view of nanotechnology, with more emphasis on its societal implications than the details of how such inventions could actually be created. Molecular nanotechnology is a proposed approach which involves manipulating single molecules in finely controlled, deterministic ways. This is more theoretical than the other subfields and is beyond current capabilities. Nanorobotics centers on self-sufficient machines of some functionality operating at the nanoscale. There are hopes for applying nanorobots in medicine, but it may not be easy to do such a thing because of several drawbacks of such devices. Nevertheless, progress on innovative materials and methodologies has been demonstrated with some patents granted about new nanomanufacturing devices for future commercial applications, which also progressively helps in the development towards nanorobots with the use of embedded nanobioelectronics concepts. Productive nanosystems are "systems of nanosystems" which will be complex nanosystems that produce atomically precise parts for other nanosystems, not necessarily using novel nanoscale-emergent properties, but well-understood fundamentals of manufacturing. Because of the discrete (i.e. atomic) nature of matter and the possibility of exponential growth, this stage is seen as the basis of another industrial revolution. Mihail Roco, one of the architects of the USA's National Nanotechnology Initiative, has proposed four states of nanotechnology that seem to parallel the technical progress of the Industrial Revolution, progressing from passive nanostructures to active nanodevices to complex nanomachines and ultimately to productive nanosystems. Programmable matter seeks to design materials whose properties can be easily, reversibly and externally controlled though a fusion of information science and materials science.Due to the popularity and media exposure of the term nanotechnology, the words picotechnology and femtotechnology have been coined in analogy to it, although these are only used rarely and informally. 17
CHAPTER 6 FUTURE OF NANOTECHNOLOGY
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Future of Nanotechnology
The future of nanotechnology is completely uncharted territory. It is almost impossible to predict everything that nanoscience will bring to the world considering that this is such a young science. There is the possibility that the future of nanotechnology is very bright, that this will be the one science of the future that no other science can live without. There is also a chance that this is the science that will make the world highly uncomfortable with the potential power to transform the world. Even positive changes can make world leaders and citizens alike very nervous. One of the top concerns regarding the future of nanoscience includes molecular manufacturing, which would be the ability to bring materials to life from the simple molecular reconstruction of everyday objects. This technology could end world hunger. At the same time, this process could lead to experimental molecular manufacturing with live beings. The future of nanotechnology could improve the outlook for medical patients with serious illnesses or injuries. Physicians could theoretically study nano surgery and be able to attack illness and injury at the molecular level. This, of course, could eradicate cancer as the surgical procedures would be done on the cellular base. Cancer cells would be identified, removed, and the surgical implantation of healthy cells would soon follow. Moreover, there would be an entire nano surgical field to help cure everything from natural aging to diabetes to bone spurs. There would be almost nothing that couldn’t be repaired (eventually) with the introduction of nano surgery. The future of nanotechnology could very well include the use of nanorobotics. These nanorobots have the potential to take on human tasks as well as tasks that humans could never complete. The rebuilding of the depleted ozone layer could potentially be able to be performed. But there are certain threats related to nanotechnology about which there is a concern among scientists all over the world. The potential disadvantages of nanotechnology: As impressive as nanotechnology might be, there are also potential disadvantages of nanotechnology. Some of the problems with nanoscience are practical while others fall under the ethical realm. ? Practical problems include everything from the need for mass produced forms of nanotechnology that may or may not be possible. 19
? ?
Ethical problems include everything from the potential direction nanotechnology might take to the problems with the possible effects of the products created. One of the potential disadvantages of nanotechnology includes the potential for mass poisoning over a period of time. While nanoscience can produce all kinds of new and improved products, the particles that are created are so incredibly small that they may very well cause eventual health problems in the consumers that use them. Since almost everyone uses a product that has been touched by nanotechnology it is possible that the eventual health effects could be large scale.
?
Mass poisoning could only happen if the coatings that nanotechnology has the potential to produce include poisonous microparticles that can cross over into the brain. There is a barrier between the blood stream and the brain known as the blood— brain barrier. Coating all of our products with particles that are small enough to cross over this barrier runs the risk of creating a mass poisoning. Fortunately, the scientists that are able to study nanotechnology have already considered this possibility and there are very strict guidelines that will help detract from this potential risk.
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Another potential problem with nanotechnology is the lack of our own knowledge. We know that we can create materials with nanotechnology but we still have to stop and understand the impact of the creation of these products will have on the nanoscale. If we change the structure of material on the nano level without understanding the potential impact on the nanoscale, we risk creating a whole world of materials that have atoms that actually do not fit together cohesively.
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There are some potential disadvantages of nanotechnology that fall in the realm of both the practical and the ethical. If nanotechnology can help the human body recover from illness or injury then it is quite possible that nanotechnology can create an altered human state. We could potentially be able to create a human race that is engineered and altered to become hyper—intelligent and super strong. The serious complications with such issues include the idea that the scientific technology would only be available to those who can afford it. That would mean there would be an underclass of people; the people we are now.
?
There is a host of potential weaponry that could be produced on a molecular level. For any scientist, the potential to engineer diseases and create lethal weaponry that can’t
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even be seen is an ethical quagmire. Even more distressing is whether or not other countries that have nanotechnology capabilities will create these weapons. While it sounds as though the disadvantages of nanotechnology will be the end of the world, this is not really the case. With all the good any science can do, there is always the capability of engineering evil potential. There is a system of checks and balances in place to help prevent the mishandling of scientific research and capabilities. There is also not a great likelihood that most of the potential disadvantages will come to fruition. Rather, it is more likely that the ethical questions and concerns will be addressed as the potential for actual development and practical use comes into play. Most of the concerns that scientists and ethical experts are concerned with will not be a realistic potential for a long time to come.
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CHAPTER 7 CONCLUSION
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Conclusion
The future of nanotechnology rests in the hands of the current scientists that are ready and able to help guide this very young science into the next realm. There are those who fear the future of nanoscience and there are those who are ready to embrace it. Walking a careful line in cohesive junction with human interests is going to be a tricky but worthwhile accomplishment. There is a possibility that the future of nanotechnology could also be the end of the science. There is a great burden on the scientists of nanotechnology. These men and women have to be able to keep the progress in play while keeping the interest in nanotechnology alive despite the potential limitations. Nanotechnology is already quietly expected within the scientific community to be the answer to the world’s problems. Just like the previous answer to the world’s problems the human element cannot be factored in until the future becomes the present. Much of the funding for nano—research may very well require something amazing in order to continue. The funding that keeps nanotechnology alive is invested in the potential future progress that this technology promises. If it fails to deliver at least some of the potential, funding and interest might vanish right before the eyes of the scientists who spend their lives trying to increase life’s wonders through the manipulation of atoms and molecules. Calls for tighter regulation of nanotechnology have occurred alongside a growing debate related to the human health and safety risks associated with nanotechnology. Furthermore, there is significant debate about who is responsible for the regulation of nanotechnology. Thus it is important to look upto the disadvantages of nanotechnology but its need in the coming generation can force us to overlook a few milder disadvantages and accept nanotechnology as a new dimension of life. What is needed is to constitute control measures regarding nanotechnology before making its applications available to common man. The advancements forecasted by the use of nanotechnology cannot be neglected and one can accept a entirely new world once nanotechnology will emerge as a new science frontier overcoming its drawbacks.
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References Books:
? ? ? Drexler, Eric. Engines of Creation 2.0: The Coming Era of Nanotechnology. York, PA: WOWIO Books, 2007. Editors of Scientific American. Understanding Nanotechnology. New York: Warner Books, 2002. Ratner, Mark and Daniel Ratner. Nanotechnology: A Gentle Introduction to the Next Big Idea. Upper Saddle River, NH: Prentice Hall, 2003.
Websites:
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Eric Drexler: Personal website of perhaps the world's best-known nanotechnology pioneer.
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Nanotechnology photos: The Centre for Nanoscale Materials (CNM) at Argonne National Laboratory publishes some excellent pictures of nanotechnology research under a Creative Commons Licence, allowing you to use them freely providing you give appropriate credit.
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http://www.explainthatstuff.com/nanotechnologyforkids.html
Press releases:
? ?
Clemson, Hitachi unveil state-of-the-art electron microscope (ANDERSON, SC) Electricity from the nose: Engineers make power from human
respiration (MADISON, WI)
?
Rice physicists move one step closer to quantum computer: 'Electron superhighway' could pave way for creation of elusive quantum-particle pairs (HOUSTON, TX)
?
Research and Markets: Updated Cardiovascular Drug Delivery Study - Examining Technological Innovation, Key Players and Markets (2010 to 2020) (DUBLIN, IRELAND)
?
SLAC, Stanford Materials Scientists Develop Topological Insulator With a Switch (PALO ALTO, CA)
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doc_190573179.pdf
1
INTRODUCTION
Objective: The purpose of this report is to explore about Nanotechnology an emerging field of science and bring to the knowledge the various advancements achieved in this field. The report provide a thorough knowledge about works of various scientists in the field of nanotechnology and what benefits this field can bring into human lives.
Limitations:
1. Since nanotechnology is a huge field, time constraints proved to be a limitation in acquiring greater details about the field. 2. Inability to reach and speak to various scientists involved with studies and exploration of the field limited the scope of study. 3. Practical viewing of nanotechnological material development was also a limitation factor since the research institutes are located far away in the country.
This report is made for all interested readers without aiming particularly at science savvy readers. Nanotechnology is a vast and very technical subject to explain thus the focus behind this project has been to make it as simple as possible. The report explains what nanotechnology is and also various materials invented through it which are not very well known to an ordinary man as yet. Further the report also explains about the possibilities of generation of extremely minute nanobots which can be infused in a human bodies to achieve various medical aids and powerful treatments.
Nanotechnology (sometimes shortened to "nanotech") is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres. Quantum mechanical effects are important at this quantum-realm scale. Nanotechnology is very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to investigating whether we can directly control matter on the atomic scale. Nanotechnology entails the application of fields of science as diverse as surface science, organic chemistry, molecular biology, semiconductor physics, microfabrication, etc.
2
The Nanoscale: Ordinary objects are absolutely huge measured on what scientists call the nanoscale. Various objects length in nanometers is as computed below:
? ? ? ? ? ? ? ? ? ? ?
Atom: ~0.1 nanometers. Atoms in a molecule: ~0.15 nanometers apart. DNA double-helix: ~2 nanometers in diameter. Typical protein: ~10 nanometers long. Computer transistor (switch): ~100-200 nanometers wide. Typical bacteria: ~200 nanometers long. Human hair: ~10,000 nanometers in diameter. One piece of paper: ~100,000 nanometers thick. Girl 1.2 m (4ft) tall: ~1200 million nanometers tall. Man 2m (6.5 ft) tall ~ 2000 million nanometers tall. Empire State Building: 381m (1250 ft) tall: ~381,000 million nanometers tall.
This shows that how minute is a nanoscale as compared to an ordinary meter scale.
3
CHAPTER 2 BACKGROUND OF NANOTECHNOLOGY
4
Background of Nanotechnology
The brilliant American physicist Richard Feynman (1918–1988) is widely credited with kickstarting modern interest in nanotechnology. In 1959, in a famous after-dinner speech called "There's plenty of room at the bottom," the ever-imaginative Feynman speculated about an incredibly tiny world where people could use tiny tools to rearrange atoms and molecules. By 1974, Japanese engineering professor Norio Taniguchi had named this field
"nanotechnology." Nanotechnology really took off in the 1980s. That was when nanotech-evangelist Dr K. Eric Drexler first published his book Engines of Creation: The Coming Era of Nanotechnology. It was also the decade when microscopes appeared that were capable of manipulating atoms and molecules on the nanoscale. In 1991, carbon nanotubes were discovered by another Japanese scientist, Sumio Iijima, opening up huge interest in new engineering applications. The graphite in pencils is a soft form of carbon. In 1998, some American scientists built themselves another kind of pencil from a carbon nanotube and then used it, under a microscope, to write the words "NANOTUBE NANOPENCIL" with letters only 10 nanometers across. Stunts like this captured the public imagination, but they also led to nanotechnology being recognized and taken seriously at the highest political levels. In 2000, President Bill Clinton sealed the importance of nanotechnology when he launched a major US government program called the National Nanotechnology Initiative (NNI), designed to fund groundbreaking research and inspire public interest.
5
CHAPTER 3 NANOSCIENCE
6
Nanoscience
Our lives have some meaning on a scale of meters, but it's impossible to think about ordinary, everyday existence on a scale 1000 times smaller than even a fly's eye. We can't really think about problems like AIDS, world poverty, or global warming, because they lose all meaning on the nanoscale. Yet the nanoscale—the world where atoms, molecules (atoms joined together), proteins, and cells rule —is a place where science and technology gain an entirely new meaning. By zooming in to the nanoscale, we can figure out how some of the puzzling things in our world actually work by seeing how atoms and molecules make them happen. The nanoscale is good because it lets us do nanoscience: it helps us understand why things happen by studying them at the smallest possible scale. Once we understand nanoscience, we can do some nanotechnology: we can put the science into action to help solve our problems. That's what the word "technology" means and it's how technology (applied science) differs from pure science, which is about studying things for their own sake.
Nanoscale importance: It turns out there are some very interesting things about the nanoscale. Lots of substances behave very differently in the world of atoms and molecules. For example, the metal copper is transparent on the nanoscale while gold, which is normally unreactive, becomes chemically very active. Carbon, which is quite soft in its normally occurring form (graphite), becomes incredibly hard when it's tightly packed into a nanoscopic arrangement called a nanotube. In other words, materials can have different physical properties on the nanoscale even though they're still the same materials. On the nanoscale, it's easier for atoms and molecules to move around and between one another, so the chemical properties of materials can also be different. Nanoparticles have much more surface area exposed to other nanoparticles, so they are very good as catalysts (substances that speed up chemical reactions). One reason for these differences is that different factors become important on the nanoscale. In our everyday world, gravity is the most important force we encounter: it dominates everything around us, from the way our hair hangs down around our head to the way Earth has different seasons at different times of year. But on the nanoscale, gravity is much less 7
important than the electromagnetic forces between atoms and molecules. Factors like thermal vibrations (the way atoms and molecules store heat by vibrating) also become extremely significant. In short, science rules get altered when we talk for objects at nonoscale. Methods to work on a nanoscale: Scientists have developed electron microscopes that allow us to "see" things on the nanoscale and also manipulate them. They're called atomic force microscopes (AFMs), scanning probe microscopes (SPMs), and scanning tunneling microscopes (STMs).
Figure 3.1: The eight tiny probe tips on the Atomic Force Microscope (AFM) built into NASA's Phoenix Mars Lander. The tip enlarged in the circle is the same size as a smoke particle at its base (2 microns).
The basic idea of an electron microscope is to use a beam of electrons to see things that are too small to see using a beam of light. A nanoscopic microscope uses electronic and quantum effects to see things that are even smaller. It also has a tiny probe on it that can be used to shift atoms and molecules around and rearrange them like tiny building blocks. In 1989, IBM researcher Don Eigler used a microscope like this to spell out the word I-B-M by moving individual atoms into position. Other scientists have used similar techniques to draw pictures of nanoscopic guitars, books, and all kinds of other things. These are mostly frivolous exercises, designed to wow people with nanopower. But they also have important practical 8
applications. There are lots of other ways of working with nanotechnology, including molecular beam epitaxy, which is a way of growing single crystals one layer of atoms at a time.
9
CHAPTER 4 APPLICATIONS OF NANOTECHNOLOGY
10
Applications of Nanotechnology
Most of nanotechnology's benefits will happen decades in the future, but it's already helping to improve our world in many different ways. We tend to think of nanotechnology as something new and alien, perhaps because the word "technology" implies artificial and human-made, but life itself is an example of nanotechnology: proteins, bacteria, viruses, and cells all work on the nanoscopic scale. Nanomaterials:
Figure 4.1: Making an electric circuit with carbon nanotubes. A carbon nanotube (shown here in light blue at the top) is connected to an electricity supply using aluminium (shown in dark blue at the bottom).
There are lot many nanotechnologically devised materials produced which we even might be using without knowing the technology behind. We might be wearing nanotechnology pants, walking on a nanotechnology rug, sleeping on nanotechnology sheets, or hauling nanotechnology luggage to the airport. All these products are made from fabrics coated with "nanowhiskers." These tiny surface fibers are so small that dirt cannot penetrate into them, which means the deeper layers of material stay clean. Some brands of sunscreens use nanotechnology in a similar way. They coat our skin with a layer of
nanoscopic titanium dioxide or zinc oxide that blocks out the Sun's harmful ultraviolet rays. Nano-coatings are also appearing on scratch-resistant car bumpers, anti-slip steps on vans and buses, corrosion resistant paints, and wound dressings.
11
Carbon nanotubes are among the most exciting of nanomaterials. These rod-shaped carbon molecules are roughly one nanometer across. Although they're hollow, their densely packed structure makes them incredibly strong and they can be grown into fibers of virtually any length. NASA scientists have recently proposed carbon nanotubes could be used to make a gigantic elevator stretching all the way from Earth into space. Equipment and people could be shuttled slowly up and down this "carbon ladder to the stars," saving the need for expensive rocket flights. Nanochips:
Figure 4.2: a single molecule of the semiconductor material cadmium sulfide
One form of nanotechnology we all use is microelectronics. The "micro" part of that word suggests computer chips work on the microscopic scal. But since terms like "microchip" were coined in the 1970s, electronic engineers have found ways of packing even more transistor switches into circuits to make computers that are smaller, faster, and cheaper than ever before. This constant increase in computing power goes by the name of Moore's Law, and nanotechnology will ensure it continues well into the future. Everyday transistors in the early 21st-century are just 100-200 nanometers wide, but cutting-edge experiments are already developing much smaller devices. In 1998, scientists made a transistor from a single carbon nanotube.
12
And it's not just the chips inside computers that use nanotechnology. The displays on everything from iPods and cellphones to laptops and flatscreen TVs are shifting to organic light-emitting diodes (OLEDs), made from plastic films built on the nanoscale. Nanomachines:
Figure 4.3: The world's smallest chain drive. An example of a nanomachine, this nanotechnology "bike chain" and gear system was developed by scientists at Sandia National Laboratory
Figure 4.4: These nanogears were made by attaching benzene
molecules (outer white blobs) to the outsides of carbon nanotubes (inner gray rings)
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One of the most exciting areas of nanotechnology is the possibility of building incredibly small machines—things like gears, switches, pumps, or engines—from individual atoms. Nanomachines could be made into nanorobots (sometimes called "nanobots") that could be injected into our bodies to carry out repairs or sent into hazardous or dangerous environments, perhaps to clean up disused nuclear power plants. As is so often the case, nature leads humans here. Scientists have already found numerous examples of nanomachines in the natural world. For example, a common bacteria called E.coli can build itself a little nanotechnology tail that it whips around like a kind of propeller to move it closer to food. Making nanomachines is also known as molecular manufacturing and molecular nanotechnology (MNT).
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CHAPTER 5 CURRENT RESEARCH
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Current Research
The current research approaches can be classified as follows: 1. Top-down approaches: These seek to create smaller devices by using larger ones to direct their assembly. Many technologies that descended from conventional solid-state silicon methods for fabricating microprocessors are now capable of creating features smaller than 100 nm, falling under the definition of nanotechnology. Giant magnetoresistance-based hard drives already on the market fit this description, as do atomic layer deposition (ALD) techniques. Peter Grünberg and Albert Fert received the Nobel Prize in Physics in 2007 for their discovery of Giant magnetoresistance and contributions to the field of spintronics. Solid-state techniques can also be used to create devices known as nanoelectromechanical systems or NEMS, which are related to microelectromechanical systems or MEMS. Focused ion beams can directly remove material, or even deposit material when suitable pre-cursor gasses are applied at the same time. For example, this technique is used routinely to create sub-100 nm sections of material for analysis in Transmission electron microscopy. Atomic force microscope tips can be used as a nanoscale "write head" to deposit a resist, which is then followed by an etching process to remove material in a topdown method. 2. Functional approaches: These seek to develop components of a desired functionality without regard to how they might be assembled. Molecular scale electronics seeks to develop molecules with useful electronic properties. These could then be used as single-molecule components in a nanoelectronic device. Synthetic chemical methods can also be used to create synthetic molecular motors, such as in a so-called nanocar. 3. Biomimetic approaches: Bionics or biomimicry seeks to apply biological methods and systems found in nature, to the study and design of engineering systems and modern technology. Biomineralization is one example of the systems studied. Bionanotechnology is the use of biomolecules for 16
applications in nanotechnology, including use of viruses. Nanocellulose is a potential bulk-scale application. 4. Speculative: These subfields seek to anticipate what inventions nanotechnology might yield, or attempt to propose an agenda along which inquiry might progress. These often take a big-picture view of nanotechnology, with more emphasis on its societal implications than the details of how such inventions could actually be created. Molecular nanotechnology is a proposed approach which involves manipulating single molecules in finely controlled, deterministic ways. This is more theoretical than the other subfields and is beyond current capabilities. Nanorobotics centers on self-sufficient machines of some functionality operating at the nanoscale. There are hopes for applying nanorobots in medicine, but it may not be easy to do such a thing because of several drawbacks of such devices. Nevertheless, progress on innovative materials and methodologies has been demonstrated with some patents granted about new nanomanufacturing devices for future commercial applications, which also progressively helps in the development towards nanorobots with the use of embedded nanobioelectronics concepts. Productive nanosystems are "systems of nanosystems" which will be complex nanosystems that produce atomically precise parts for other nanosystems, not necessarily using novel nanoscale-emergent properties, but well-understood fundamentals of manufacturing. Because of the discrete (i.e. atomic) nature of matter and the possibility of exponential growth, this stage is seen as the basis of another industrial revolution. Mihail Roco, one of the architects of the USA's National Nanotechnology Initiative, has proposed four states of nanotechnology that seem to parallel the technical progress of the Industrial Revolution, progressing from passive nanostructures to active nanodevices to complex nanomachines and ultimately to productive nanosystems. Programmable matter seeks to design materials whose properties can be easily, reversibly and externally controlled though a fusion of information science and materials science.Due to the popularity and media exposure of the term nanotechnology, the words picotechnology and femtotechnology have been coined in analogy to it, although these are only used rarely and informally. 17
CHAPTER 6 FUTURE OF NANOTECHNOLOGY
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Future of Nanotechnology
The future of nanotechnology is completely uncharted territory. It is almost impossible to predict everything that nanoscience will bring to the world considering that this is such a young science. There is the possibility that the future of nanotechnology is very bright, that this will be the one science of the future that no other science can live without. There is also a chance that this is the science that will make the world highly uncomfortable with the potential power to transform the world. Even positive changes can make world leaders and citizens alike very nervous. One of the top concerns regarding the future of nanoscience includes molecular manufacturing, which would be the ability to bring materials to life from the simple molecular reconstruction of everyday objects. This technology could end world hunger. At the same time, this process could lead to experimental molecular manufacturing with live beings. The future of nanotechnology could improve the outlook for medical patients with serious illnesses or injuries. Physicians could theoretically study nano surgery and be able to attack illness and injury at the molecular level. This, of course, could eradicate cancer as the surgical procedures would be done on the cellular base. Cancer cells would be identified, removed, and the surgical implantation of healthy cells would soon follow. Moreover, there would be an entire nano surgical field to help cure everything from natural aging to diabetes to bone spurs. There would be almost nothing that couldn’t be repaired (eventually) with the introduction of nano surgery. The future of nanotechnology could very well include the use of nanorobotics. These nanorobots have the potential to take on human tasks as well as tasks that humans could never complete. The rebuilding of the depleted ozone layer could potentially be able to be performed. But there are certain threats related to nanotechnology about which there is a concern among scientists all over the world. The potential disadvantages of nanotechnology: As impressive as nanotechnology might be, there are also potential disadvantages of nanotechnology. Some of the problems with nanoscience are practical while others fall under the ethical realm. ? Practical problems include everything from the need for mass produced forms of nanotechnology that may or may not be possible. 19
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Ethical problems include everything from the potential direction nanotechnology might take to the problems with the possible effects of the products created. One of the potential disadvantages of nanotechnology includes the potential for mass poisoning over a period of time. While nanoscience can produce all kinds of new and improved products, the particles that are created are so incredibly small that they may very well cause eventual health problems in the consumers that use them. Since almost everyone uses a product that has been touched by nanotechnology it is possible that the eventual health effects could be large scale.
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Mass poisoning could only happen if the coatings that nanotechnology has the potential to produce include poisonous microparticles that can cross over into the brain. There is a barrier between the blood stream and the brain known as the blood— brain barrier. Coating all of our products with particles that are small enough to cross over this barrier runs the risk of creating a mass poisoning. Fortunately, the scientists that are able to study nanotechnology have already considered this possibility and there are very strict guidelines that will help detract from this potential risk.
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Another potential problem with nanotechnology is the lack of our own knowledge. We know that we can create materials with nanotechnology but we still have to stop and understand the impact of the creation of these products will have on the nanoscale. If we change the structure of material on the nano level without understanding the potential impact on the nanoscale, we risk creating a whole world of materials that have atoms that actually do not fit together cohesively.
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There are some potential disadvantages of nanotechnology that fall in the realm of both the practical and the ethical. If nanotechnology can help the human body recover from illness or injury then it is quite possible that nanotechnology can create an altered human state. We could potentially be able to create a human race that is engineered and altered to become hyper—intelligent and super strong. The serious complications with such issues include the idea that the scientific technology would only be available to those who can afford it. That would mean there would be an underclass of people; the people we are now.
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There is a host of potential weaponry that could be produced on a molecular level. For any scientist, the potential to engineer diseases and create lethal weaponry that can’t
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even be seen is an ethical quagmire. Even more distressing is whether or not other countries that have nanotechnology capabilities will create these weapons. While it sounds as though the disadvantages of nanotechnology will be the end of the world, this is not really the case. With all the good any science can do, there is always the capability of engineering evil potential. There is a system of checks and balances in place to help prevent the mishandling of scientific research and capabilities. There is also not a great likelihood that most of the potential disadvantages will come to fruition. Rather, it is more likely that the ethical questions and concerns will be addressed as the potential for actual development and practical use comes into play. Most of the concerns that scientists and ethical experts are concerned with will not be a realistic potential for a long time to come.
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CHAPTER 7 CONCLUSION
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Conclusion
The future of nanotechnology rests in the hands of the current scientists that are ready and able to help guide this very young science into the next realm. There are those who fear the future of nanoscience and there are those who are ready to embrace it. Walking a careful line in cohesive junction with human interests is going to be a tricky but worthwhile accomplishment. There is a possibility that the future of nanotechnology could also be the end of the science. There is a great burden on the scientists of nanotechnology. These men and women have to be able to keep the progress in play while keeping the interest in nanotechnology alive despite the potential limitations. Nanotechnology is already quietly expected within the scientific community to be the answer to the world’s problems. Just like the previous answer to the world’s problems the human element cannot be factored in until the future becomes the present. Much of the funding for nano—research may very well require something amazing in order to continue. The funding that keeps nanotechnology alive is invested in the potential future progress that this technology promises. If it fails to deliver at least some of the potential, funding and interest might vanish right before the eyes of the scientists who spend their lives trying to increase life’s wonders through the manipulation of atoms and molecules. Calls for tighter regulation of nanotechnology have occurred alongside a growing debate related to the human health and safety risks associated with nanotechnology. Furthermore, there is significant debate about who is responsible for the regulation of nanotechnology. Thus it is important to look upto the disadvantages of nanotechnology but its need in the coming generation can force us to overlook a few milder disadvantages and accept nanotechnology as a new dimension of life. What is needed is to constitute control measures regarding nanotechnology before making its applications available to common man. The advancements forecasted by the use of nanotechnology cannot be neglected and one can accept a entirely new world once nanotechnology will emerge as a new science frontier overcoming its drawbacks.
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References Books:
? ? ? Drexler, Eric. Engines of Creation 2.0: The Coming Era of Nanotechnology. York, PA: WOWIO Books, 2007. Editors of Scientific American. Understanding Nanotechnology. New York: Warner Books, 2002. Ratner, Mark and Daniel Ratner. Nanotechnology: A Gentle Introduction to the Next Big Idea. Upper Saddle River, NH: Prentice Hall, 2003.
Websites:
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Eric Drexler: Personal website of perhaps the world's best-known nanotechnology pioneer.
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Nanotechnology photos: The Centre for Nanoscale Materials (CNM) at Argonne National Laboratory publishes some excellent pictures of nanotechnology research under a Creative Commons Licence, allowing you to use them freely providing you give appropriate credit.
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http://www.explainthatstuff.com/nanotechnologyforkids.html
Press releases:
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Clemson, Hitachi unveil state-of-the-art electron microscope (ANDERSON, SC) Electricity from the nose: Engineers make power from human
respiration (MADISON, WI)
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Rice physicists move one step closer to quantum computer: 'Electron superhighway' could pave way for creation of elusive quantum-particle pairs (HOUSTON, TX)
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Research and Markets: Updated Cardiovascular Drug Delivery Study - Examining Technological Innovation, Key Players and Markets (2010 to 2020) (DUBLIN, IRELAND)
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SLAC, Stanford Materials Scientists Develop Topological Insulator With a Switch (PALO ALTO, CA)
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