Abstract:
Nanotechnology is defined as the study and use of structures between 1 nanometer and 100 nanometers in size. To give you an idea of how small that is, it would take eight hundred 100 nanometer particles side by side to match the width of a human hair. The last decade has been seen the thrilling development in material science in the nanometer scale. Recently people start to realize the exciting potential of biomolecules in nanotechnology. A scientific advancements associated with molecular biology and nanofabrication technology now offer , for the first time, the potential of engineering functional hybrid organic/ inorganic nano-mechanical systems.Truly revolutionary nanotechnology products, materials and applications, such as nanorobotics, are years in the future (some say only a few years; some say many years). What qualifies as "nanotechnology" today is basic research and development that is happening in laboratories all over the world. "Nanotechnology" products that are on the market today are mostly gradually improved products (using evolutionary nanotechnology) where some form of nanotechnology enabled material or nanotechnology process is used in the manufacturing process. In their on going quest to improve existing products by creating smaller components and better performance materials, all at a lower cost, the number of companies that will manufacture "nanoproducts" (by this definition) will grow very fast and soon make up the majority of all companies across many industries.
Introduction to Nanotechnology

Definition of nan'o•tech•nol'o•gy So what exactly is nanotechnology? One of the problems facing nanotechnology is the confusion about its definition. Most definitions revolve around the study and control of phenomena and materials at length scales below 100 nm and quite often they make a comparison with a human hair, which is about 80,000 nm wide. Some definitions include a reference to molecular systems and devices and nanotechnology 'purists' argue that any definition of nanotechnology needs to include a reference to "functional systems". The inaugural issue of Nature Nanotechnology asked 13 researchers from different areas what nanotechnology means to them and the responses, from enthusiastic to sceptical, reflect a variety of perspectives.


Human hair fragment and a network of single-walled carbon nanotubes)
It seems that a size limitation of nanotechnology to the 1-100 nm range, the area where size-dependant quantum effects come to bear, would exclude numerous materials and devices, especially in the pharamaceutical area, and some experts caution against a rigid definition based on a sub-100 nm size. We found a good definition that is practical and unconstrained by any arbitrary size limitations .
The design, characterization, production, and application of structures, devices, and systems by controlled manipulation of size and shape at the nanometer scale (atomic, molecular, and macromolecular scale) that produces structures, devices, and systems with at least one novel/superior characteristic or property.
The Potential of Nanotechnology for Molecular Manufacturing





Nanotechnologies are tools that measure and manipulate phenomena and objects at the nanoscale. Molecular manufacturing is the willful use of these two activities to create new objects or phenomena. The question of whether it is possible to achieve a stage in the foreseeable future when molecular manufacturing using nanotechnologies might be viable, and if so how to develop the field, is a point of contention in both scientific and policy circles. A framework for understanding the scope of this topic — possible benefits, development risks, and policy options — is presented, but it is not the intention of the authors to provide a definitive road map for future scientific and technological development; nor is it believed by the authors that such a detailed analysis would at present yield a fully credible road map given the immature nature of the field. Rather, it is the contention of this report that though important breakthroughs have been realized, much significant basic and applied research remains to be undertaken to realistically assess the far-term viability of many of the emerging concepts. However, a careful and objective technology feasibility assessment could help stimulate near-term interim achievements of great merit while preventing technological surprises from foreign players. Molecular nanotechnology is the anticipated future ability to manufacture a wide range of macroscopic structures (including new materials, computers, and other complex gadgetry) to atomic precision. Nanotechnology will give us unprecedented control over the structure of matter.
Carbon Nanotubes
A practical guide to understanding their properties, applications production methods, markets and utility.
History of CNT
In 1980 we knew of only three forms of carbon, namely diamond, graphite, and amorphous carbon. Today we know there is a whole family of other forms of carbon. The first to be discovered was the hollow, cagelike buckminsterfullerene molecule - also known as the buckyball, or the C60 fullerene. There are now thirty or more forms of fullerenes, and also an extended family of linear molecules, carbon nanotubes.The important fact for nanotechnology is that useful dopant atoms can be placed inside the hollow fullerene ball. Atoms contained within the fullerene are said to be endohedral.
Properties of CNTs
There are many useful and unique properties of cnt’s
The list includes:
• High Electrical Conductivity
• Very High Tensile Strength
• Highly Flexible- can be bent considerably without damage
• Very Elastic ~18% elongation to failure
• High Thermal Conductivity
• Low Thermal Expansion Coefficient
• Good Field Emission of Electrons
• Highly Absorbent
• High Aspect Ratio (length = ~1000 x diameter)
Applications
The special nature of carbon combined with the molecular perfection of single-walled nanotubes to endow them with exceptional material properties, such as very high electrical and thermal conductivity, strength, stiffness, and toughness.
This aspect is part of the unique story of CNTs. CNTs are an example of true nanotechnology: they are under 100 nanometers in diameter, but are molecules that can be manipulated chemically and physically in very useful way
CNT Ceramics
A ceramic material reinforced with carbon nanotubes has been made by materials scientists at UC Davis. The new material is far tougher than conventional ceramics, conducts electricity and can both conduct heat and act as a thermal barrier, depending on the orientation of the nanotubes.

Biomedical Applications
The exploration of CNTs in biomedical applications is just underway, but has significant potential. Since a large part of the human body consists of carbon, it is generally though of as a very biocompatible material. Cells have been shown to grow on CNTs, so they appear to have no toxic effect. The cells also do not adhere to the CNTs, potentially giving rise to applications such as coatings for prosthetics and surgical implants. The ability to functionalize the sidewalls of CNTs also leads to biomedical applications such as vascular stents, and neuron growth and regeneration. It has also been shown that a single strand of DNA can be bonded to a nanotube, which can then be successfully inserted into a cell; this has potential applications in gene therap
Air, Water, and Gas Filtration
Many researchers and corporations have already developed CNT based air and water filtration devices. It has been reported that these filters can not only block the smallest particles but also kill most bacteria. This is another area where CNTs have already been commercialized and products are on the market now. Someday CNTs may be used to filter other liquids such as fuels and lubricants as well.

CNTs have many unique and desirable properties. Although many applications may take significant investments of time and money to develop to reach commercial viability, there are plenty of applications today in which CNTs add significant benefits to existing products with relatively low implementation costs. Most of these applications are in the polymer, composite materials, batteries, paints, plastics, ceramics, and textiles industries.

Nanotechnology is engineering and manufacturing at the molecular scale, and the application of nanotechnology to medicine is called nanomedicine


Medical Techniques Using Nanotech

Medical theory and technique today are a vast improvement over the state of the art a century ago. However, by comparison with what could be, medical practice today can only be described as primitive.
Nanotechnology and Nanomedicine:
“There is a growing sense in the scientific and technical community that we are about to enter a golden new era,”
We are about to be able to build things that work on the smallest possible length scales, atom by atom,” Smalley said. “Over the past century we have learned about the workings of biological nanomachines to an incredible level of detail, and the benefits of this knowledge are beginning to be felt in medicine.

Burgeoning interest in the medical applications of nanotechnology has led to the emergence of a new field called nanomedicine [2, 3]. Most broadly, nanomedicine is the process of diagnosing, treating, and preventing disease and traumatic injury, of relieving pain, and of preserving and improving human health, using molecular tools and molecular knowledge of the human body.

It is most useful to regard the emerging field of nanomedicine as a set of three mutually overlapping and progressively more powerful technologies. First, in the relatively near term, nanomedicine can address many important medical problems by using nanoscale-structured materials that can be manufactured today
Surgery creates huge wounds which require days to heal. Cancer therapy usually aims to be as destructive as possible, without wiping out anything too important. Most of our drugs were discovered by trial and error, and their side effects are sometimes drastic


Advanced Automation for Space Missions


The painting above was created by Mr. Rick Guidice. It captures the spirit of the space missions described in this study. In the center of the picture are human beings who, we believe, will continue to play a controlling role in future space missions. To the right of the circle are two space systems representing a partially automated Space Manufacturing Facility which would eventually utilize nonterrestrial resources. In the upper-right corner is Saturn attended by its largest natural satellite Titan, the proposed destination of our advanced space-exploration mission. The upper-left corner depicts the deepest reaches of the Cosmos that humans someday may explore. At center left is the Earth, which is under intensive study by an intelligent Earth sensing information system that is able to obtain and deliver data in a far more effective manner than present-day methods. In the lower left corner, a lunar manufacturing facility rises from the surface of the Moon. Someday, such a factory might replicate itself, or at least produce most of its own components, so that the number of facilities could grow very rapidly from a single seed.
Since the late 1950s NASA has devoted itself to the acquisition and communication of information about the Earth, the planets, the stars, and the Universe. It has launched an impressive series of spectacularly successful exploration missions and numerous Earth-orbiting satellites that have added to an immense, growing pool of useful knowledge about terrestrial resources, weather and climatic patterns, global cartography, and the oceans


NASA Study Group on Machine Intelligence and Robotics (1977-78)
After visiting a number of NASA Centers and facilities over a two-year period, the Study Group reached four major conclusions:
• NASA is 5 to 15 years behind the leading edge in computer science and technology.
• Technology decisions are, to a great degree, dictated by specific mission goals, thus powerfully impeding NASA utilization of modern computer science and automation techniques. Unlike its pioneering work in other areas of science and technology, NASA's use of computer science has been conservative and unimaginative.
• The overall importance of machine intelligence and robotics for NASA has not been widely appreciated within the agency, and NASA has made no serious effort to attract bright, young scientists in these fields.
The advances and developments in machine intelligence and robotics needed to make future space missions economical and feasible will not happen without a major long-term commitment and centralized, coordinated support

Nanorobots the size of bacteria might one day roam peopleís bodies, rooting out disease organisms and repairing damaged tissue
Volumetric Cellular Intrusiveness of Medical Nanorobots
Medical nanorobots on cytotherapeutic missions will often need to enter the living cell to perform repairs. Such missions may require the participation of many cooperating nanorobots, or perhaps just a few but relatively large nanorobots, per cell. And so the question logically arises: How many nanorobots can safely be crammed into a single living cell? There are at least two issues here. First, how much new foreign material can be added to a cell? Second, how much of a cell’s existing volume can be replaced with foreign material with no change in total cell volume? Since we can’t yet do direct experiments with medical nanorobots and living cells, no precise answer is possible. But we can estimate the maximum volume of foreign material that the intracellular compartment might safely accommodate by examining analogous instances of cellular intrusion.



Build Small, Think Big
Nanotech is the ability to build complicated shapes and/or machines with every atom in its specified place. Chemists and biologists create molecules with every atom precisely placed--but the molecules we can build today are a tiny fraction of those that are possible. Engineers build incredibly complicated and useful machines--but even the most intricate is chock-full of wasted space. We have had several "revolutions" in technology--industrial, agricultural, medical, and computer--within the last two centuries. But each of these has only given us a small fraction of the capabilities we could have. Nanotech will let us finish the job, by being much more precise in our design and fabrication of machines and by using better materials.
Let's take a look at tiny gizmos. Start by taking apart a mechanical clock--clocks are full of small parts. Set a small metal gear on the floor, and start shrinking yourself. Shrink until you're the same size as the gear, about 200 times smaller than life-size. Hold up your hand and compare it to a tooth of the gear. They're about the same size--but the gear tooth is mostly featureless, while your hand has fingers, fingernails, muscles, blood vessels, and other working parts.
Conclusion
Nanotechnology-“Passion for Electronics, Compassion for Community.”
Nanotechnology is the integration of evolutionary and human systems for the design and fabrication of molecular devices.Nanotechnology is a careful and objective technology that measures and manipulates phenomena and objects at the nanoscale.


References:
• NASA Space Systems Technology Model: Volume 111 Opportunity Systems/Programs and Technologies, NASA, Washington, D.C ., May 1 980 Sagan, Carl, Chmn.: Machine Intelligence and Robotics:
• Robert A. Freitas Jr., “The Nanomedicine Page”; http://www.foresight.org/Nanomedicine/index.html

• Drexler K E 1992 Nanosystems: Molecular Machinery, Manufacturing, and Computation (New York: Wiley Interscience)