Nanotechnology And Its Applications

NANOTECHNOLOGY The Future is Coming Sooner Than You Think 1.

INTRODUCTION :

Nanotechnology, sometimes shortened to nanotech, refers to a field of applied science whose theme is the control of matter on an atomic and molecular scale. Generally nanotechnology deals with structures 100 nanometers or smaller, and involves developing materials or devices within that size. Nanotechnology is an umbrella term that encompasses all fields of science that operate on the nanoscale. Nanotechnology is an extremely diverse and multidisciplinary field, ranging from novel extensions of conventional device physics, to completely new approaches based upon molecular self-assembly, to developing new materials with dimensions on the nanoscale, or the scale of nothing, even to speculation on whether we can directly control matter on the atomic scale. Nanotechnology has the potential to create many new materials and devices with wideranging applications, such as in medicine, electronics, and energy production. On the other hand, nanotechnology raises many of the same issues as with any introduction of new technology, including concerns about the toxicity and environmental impact of nanomaterials, and their potential effects on global economics 2.

HOW NEW IS NANOTECHNOLOGY?

Nanotechnology was first introduced in 1959, in a talk by the Nobel Prize-winning physicist , entitled "There's Plenty of Room at the Bottom". Richard Feynman proposed using a set of conventional-sized robot arms to construct a replica of themselves, but one-tenth the original size, then using that new set of arms to manufacture an even smaller set, and so on, until the molecular scale is reached. If we had many millions or billions of such molecular-scale arms, we could program them to work together to create macro-scale products built from individual molecules — a "bottom-up manufacturing" technique, Richard Feynman as opposed to the usual technique of cutting away material until you have a completed component or product — "top-down manufacturing". In 1986, K. Eric Drexler wrote "Engines of Creation" and introduced the term nanotechnology. Scientific research really expanded over the last decade. Inventors and corporations aren't far behind -- today, more than 13,000 patents registered with the U.S. Patent Office have the word "nano" in them. K. Eric Drexler 1

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WHAT IS NANOTECHNOLOGY?

A basic definition: Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced. In its original sense, 'nanotechnology' refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products. The U.S. National Nanotechnology Initiative defines nanotechnology as: “The science, engineering, and technology related to the understanding and control of matter at the length scale of approximately 1 to 100 nanometers.”

Fundamental concepts: One nanometer (nm) is one billionth, or 10-9 of a meter. For comparison purposes, the width of an average hair is 100,000 nanometers. Human blood cells are 2,000 to 5,000 nm long, a strand of DNA has a diameter of 2.5 nm, and a line of ten hydrogen atoms is one nm.2 The last three statistics are especially enlightening. First, even within a blood cell there is a great deal of room at the nanoscale. Nanotechnology therefore holds out the promise of manipulating individual cell structure and function. Second, the ability tounderstand and manipulate matter at the level of one nanometer is closely related to the ability to understand and manipulate both matter and life at their most basic levels: the atom and the organic molecules that make up DNA.

Two main approaches are used in nanotechnology. In the "bottom-up" approach, materials and devices are built from molecularcomponents which assemble themselves chemically by principles of molecular recognition. In the "top-down" approach, nano-objects are constructed from larger entities without atomic-level control.

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HOW NANOTECHNOLOGY WORKS?

There's an unprecedented multidisciplinary convergence of scientists dedicated to the study of a world so small, we can't see it -- even with a light microscope. That world is the field of nanotechnology, the realm of atoms and nanostructures. Nanotechnology is so new; no one is really sure what will come of it. Even so, predictions range from the ability to reproduce things like diamonds and food to the world being devoured by self-replicating nanorobots.

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As small as a nanometer is, it's still large compared to the atomic scale. An atom has a diameter of about 0.1 nm. An atom's nucleus is much smaller -- about 0.00001 nm. Atoms are the building blocks for all matter in our universe. You and everything around you are made of atoms. Nature has perfected the science of manufacturing matter molecularly. For instance, our bodies are assembled in a specific manner from millions of living cells. Cells are nature's nanomachines. At the atomic scale, elements are at their most basic level. On the nanoscale, we can potentially put these atoms together to make almost anything.

PRODUCTS WITH NANOTECHNOLOGY

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You might be surprised to find out how many products on the market are already benefiting from nanotechnology. •

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Sunscreen - Many sunscreens contain nanoparticles of zinc oxide or titanium oxide. Oldersunscreen formulas use larger particles, which is what gives most sunscreens their whitish color. Smaller particles are less visible, meaning that when you rub the sunscreen into your skin, it doesn't give you a whitish tinge. Self-cleaning glass - A company called Pilkington Ingredients like zinc oxide can leave a white sheen behind. But sunscreens with offers a product they call Activ Glass, which uses zinc oxide nanoparticles rub on clear. nanoparticles to make the glass photocatalytic and hydrophilic. The photocatalytic effect means that when UV radiation from

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light hits the glass, nanoparticles become energized and begin to break down and loosen organic molecules on the glass (in other words, dirt). Hydrophilic means that when water makes contact with the glass, it spreads across the glass evenly, which helps wash the glass clean. Clothing - Scientists are using nanoparticles to enhance your clothing. By coating fabrics with a thin layer of zinc oxide nanoparticles, manufacturers can create clothes that give better protection from UV radiation. Some clothes have nanoparticles in the form of little hairs or whiskers that help repel water and other materials, making the clothing stainresistant. Scratch-resistant coatings - Engineers discovered that adding aluminum silicate nanoparticles to scratch-resistant polymer coatings made the coatings more effective, increasing resistance to chipping and scratching. Scratch-resistant coatings are common on everything from cars to eyeglass lenses. Antimicrobial bandages - Scientist Robert Burrell created a process to manufacture antibacterial bandages using nanoparticles of silver. Silver ions block microbes' cellular respiration [source: Burnsurgery.org]. In other words, silver smothers harmful cells, killing them. Swimming pool cleaners and disinfectants - EnviroSystems, Inc. developed a mixture (called a nanoemulsion) of nano-sized oil drops mixed with a bactericide. The oil particles adhere to bacteria, making the delivery of the bactericide more efficient and effective. Yoshikazu Tsuno/AFP/Getty Images Bridgestone engineers developed this Quick

Response Liquid Powder Display, a flexible New products incorporating nanotechnology are coming out every day. Wrinkle-resistant digital screen, using nanotechnology. fabrics, deep-penetrating cosmetics, liquid crystal displays (LCD) and other conveniences using nanotechnology are on the market. Before long, we'll see dozens of other products that take advantage of nanotechnology ranging from Intel microprocessors to bionanobatteries, capacitorsonly a few nanometers thick. While this is exciting, it's only the tip of the iceberg as far as how nanotechnology may impact us in the future.

Tennis, Anyone? Nanotechnology is making a big impact on the tennis world. In 2002, the tennis racket company Babolat introduced the VS Nanotube Power racket. They made the racket out of carbon nanotube-infused graphite, meaning the racket was very light, yet many times stronger than steel. Meanwhile, tennis ball manufacturer Wilson introduced the Double Core tennis ball. These balls have a coating of clay nanoparticles on the inner core. The clay acts as a sealant, making it very difficult for air to escape the ball.

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NANOWIRES AND CARBON NANOTUBES

Currently, scientists find two nano-size structures of particular interest: nanowires and carbon nanotubes. Nanowires are wires with a very small diameter, sometimes as small as 1 nanometer. Scientists hope to use them to build tiny transistors for computer chips and other electronic devices. In the last couple of years, carbon nanotubes have overshadowed nanowires. We're still learning about these structures, but what we've learned so far is very exciting. CNT is a tubular form of carbon with diameters as small as 1nm, and lengths of over 130 microns

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CNT’s exhibit extraordinary mechanical properties Young’s Modulus over 1 TPa Tensile strength approximately 200 GPa

A carbon nanotube is a nano-size cylinder of carbon atoms. Imagine a sheet of carbon atoms, which would look like a sheet of hexagons. If you roll that sheet into a tube, you'd have a carbon nanotube. Carbon nanotube properties depend on how you roll the sheet. In other words, even though all carbon nanotubes are made of carbon, they can be very different from one another based on how you align the individual atoms. With the right arrangement of atoms, you can create a carbon nanotube that's hundreds of times stronger than steel, but six times lighter. Engineers plan to make building material out of carbon nanotubes, particularly for things like cars and airplanes. Lighter vehicles would mean better fuel efficiency, and the added strength translates to increased passenger safety.

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Carbon nanotubes can also be effective semiconductors with the right arrangement of atoms. Scientists are still working on finding ways to make carbon nanotubes a realistic option for transistors in microprocessors and other electronics. Graphite vs. Diamonds What's the difference between graphite and diamonds? Both materials are made of carbon, but both have vastly different properties. Graphite is soft; diamonds are hard. Graphite conducts electricity, but diamonds are insulators and can't conduct electricity. Graphite is opaque; diamonds are usually transparent. Graphite and diamonds have these properties because of the way the carbon atoms bond together at the nanoscale.

7. MOLECULAR NANOTECHNOLOGY: A LONG-TERM VIEW Molecular nanotechnology, sometimes called molecular manufacturing, is a term given to the concept of engineered nanosystems (nanoscale machines) operating on the molecular scale. It is especially associated with the concept of a molecular assembler, a machine that can produce a desired structure or device atom-by-atom using the principles of mechanosynthesis. Manufacturing in the context of productive nanosystems is not related to, and should be clearly distinguished from, the conventional technologies used to manufacture nanomaterials such as carbon nanotubes and nanoparticles. When the term "nanotechnology" was independently coined and popularized by Eric Drexler (who at the time was unaware of an earlier usage by Norio Taniguchi) it referred to a future manufacturing technology based on molecular machine systems. The premise was that molecular scale biological analogies of 6

traditional machine components demonstrated molecular machines were possible: by the countless examples found in biology, it is known that sophisticated, stochastically optimised biological machines can be produced. It is hoped that developments in nanotechnology will make possible their construction by some other means, perhaps using biomimetic principles. However, Drexler and other researchers have proposed that advanced nanotechnology, although perhaps initially implemented by biomimetic means, ultimately could be based on mechanical engineering principles, namely, a manufacturing technology based on the mechanical functionality of these components (such as gears, bearings, motors, and structural members) that would enable programmable, positional assembly to atomic specification (PNAS-1981). The physics and engineering performance of exemplar designs were analyzed in Drexler's book Nanosystems. In general it is very difficult to assemble devices on the atomic scale, as all one has to position atoms are other atoms of comparable size and stickyness. Another view, put forth by Carlo Montemagno, is that future nanosystems will be hybrids of silicon technology and biological molecular machines. Yet another view, put forward by the late Richard Smalley, is that mechanosynthesis is impossible due to the difficulties in mechanically manipulating individual molecules. This led to an exchange of letters in the ACS publication Chemical & Engineering News in 2003. Though biology clearly demonstrates that molecular machine systems are possible, non-biological molecular machines are today only in their infancy. Leaders in research on non-biological molecular machines are Dr. Alex Zettl and his colleagues at Lawrence Berkeley Laboratories and UC Berkeley. They have constructed at least three distinct molecular devices whose motion is controlled from the desktop with changing voltage: a nanotube nanomotor, a molecular actuator, and a nanoelectromechanical relaxation oscillator. An experiment indicating that positional molecular assembly is possible was performed by Ho and Lee at Cornell University in 1999. They used a scanning tunneling microscope to move an individual carbon monoxide molecule (CO) to an individual iron atom (Fe) sitting on a flat silver crystal, and chemically bound the CO to the Fe by applying a voltage. 8.

CURRENT RESEARCH

Nanomaterials This includes subfields which develop or study materials having unique properties arising from their nanoscale dimentions. • Interface and Colloid Science has given rise to many Materials which may be useful in nanotechnology, such as carbon nanotubes Graphical representation of a and other fullerenes, and various nanoparticles rotaxane, useful as a molecular switch and nanorods.

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Nanoscale materials can also be used for bulk applications; most present commercial applications of nanotechnology are of this flavor. Progress has been made in using these materials for medical applications.

Bottom-up approaches These seek to arrange smaller components into more complex assemblies. •

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DNA nanotechnology utilizes the specificity of Watson-Crick basepairing to construct well-defined structures out of DNA and other nucleic acids. Approaches from the field of "classical" chemical synthesis also aim at designing molecules with welldefined shape (e.g. bis-peptides). More generally, molecular self-assembly seeks to use concepts of supramolecular chemistry, and molecular recognition in particular, to cause single-molecule components to automatically arrange themselves into some useful conformation.

This device transfers energy from nano-thin layers of quantum wells to nanocrystals above them, causing the nanocrystals to emit visible light.

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p-down approaches These seek to create smaller devices by using larger ones to direct their assembly. •

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Many technologies 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 for their discovery of Giant magnetoresistance and contributions to the field of spintronics in 2007. Solid-state techniques can also be used to create devices known as nanoelectromechanical systems or NEMS, which are related to microelectromechanical systems or MEMS. Atomic force microscope tips can be used as a nanoscale "write head" to deposit a chemical upon a surface in a desired pattern in a process called dip pen nanolithography. This fits into the larger subfield of nanolithography. Focussed 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.

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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. •

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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[13][14][15], but it may not be easy to do such a thing because of several drawbacks of such devices.[16] 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 concept.[17][18] Programmable matter based on artificial atoms seeks to design materials whose properties can be easily, reversibly and externally controlled. 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.

TOOLS AND TECHNIQUES

The first observations and size measurements of nano-particles were made during the first decade of the 20th century. They are mostly associated with the name of Zsigmondy who made detailed studies of gold sols and other nanomaterials with sizes down to 10 nm and less. He published a book in 1914. He used ultramicroscope that employs a dark field method for seeing particles with sizes much less than light wavelength. There are traditional techniques developed during 20th century in Interface and Colloid Science for characterizing nanomaterials. These are widely used for first generation passive nanomaterials specified in the next section. These methods include several different techniques for characterizing particle size distribution. This characterization is imperative because many materials that are expected to be nano-sized are actually aggregated in solutions. Some of methods are based on light scattering. Other apply ultrasound, such as ultrasound 9

Typical AFM setup. A microfabricated cantilever with a sharp tip is deflected by features on a sample surface, much like in a phonograph but on a much smaller scale. A laser beam reflects off the backside of the cantilever into a set of photodetectors, allowing the deflection to be measured and assembled into an image of the surface.

attenuation spectroscopy for testing concentrated nano-dispersions and microemulsions. There is also a group of traditional techniques for characterizing surface charge or zeta potential of nano-particles in solutions. This information is required for proper system stabilzation, preventing its aggregation or flocculation. These methods include microelectrophoresis, electrophoretic light scattering and electroacoustics. The last one, for instance colloid vibration current method is suitable for characterizing concentrated systems. Next group of nanotechnological techniques include those used for fabrication of nanowires, those used in semiconductor fabrication such as deep ultraviolet lithography, electron beam lithography, focused ion beam machining, nanoimprint lithography, atomic layer deposition, and molecular vapor deposition, and further including molecular self-assembly techniques such as those employing di-block copolymers. However, all of these techniques preceded the nanotech era, and are extensions in the development of scientific advancements rather than techniques which were devised with the sole purpose of creating nanotechnology and which were results of nanotechnology research. There are several important modern developments. The atomic force microscope (AFM) and the Scanning Tunneling Microscope (STM) are two early versions of scanning probes that launched nanotechnology. There are other types of scanning probe microscopy, all flowing from the ideas of the scanning confocal microscope developed by Marvin Minsky in 1961 and the scanning acoustic microscope (SAM) developed by Calvin Quate and coworkers in the 1970s, that made it possible to see structures at the nanoscale. The tip of a scanning probe can also be used to manipulate nanostructures (a process called positional assembly). Feature-oriented scanning-positioning methodology suggested by Rostislav Lapshin appears to be a promising way to implement these nanomanipulations in automatic mode. However, this is still a slow process because of low scanning velocity of the microscope. Various techniques of nanolithography such as dip pen nanolithography, electron beam lithography or nanoimprint lithography were also developed. Lithography is a top-down fabrication technique where a bulk material is reduced in size to nanoscale pattern. The top-down approach anticipates nanodevices that must be built piece by piece in stages, much as manufactured items are made. Scanning probe microscopy is an important technique both for characterization and synthesis of nanomaterials. Atomic force microscopes and scanning tunneling microscopes can be used to look at surfaces and to move atoms around. By designing different tips for these microscopes, they can be used for carving out structures on surfaces and to help guide self-assembling structures. By using, for example, featureoriented scanning-positioning approach, atoms can be moved around on a surface with scanning probe microscopy techniques. At present, it is expensive and time-consuming for mass production but very suitable for laboratory experimentation. In contrast, bottom-up techniques build or grow larger structures atom by atom or molecule by molecule. These techniques include chemical synthesis, self-assembly and positional assembly. Another variation of the bottom-up approach is molecular beam epitaxy or MBE. Researchers at Bell Telephone Laboratories like John R. Arthur. Alfred Y. Cho, and Art C. Gossard developed and implemented MBE as a research tool in the late 1960s and 1970s. 10

Samples made by MBE were key to the discovery of the fractional quantum Hall effect for which the 1998 Nobel Prize in Physics was awarded. MBE allows scientists to lay down atomically-precise layers of atoms and, in the process, build up complex structures. Important for research on semiconductors, MBE is also widely used to make samples and devices for the newly emerging field of spintronics. Newer techniques such as Dual Polarisation Interferometry are enabling scientists to measure quantitatively the molecular interactions that take place at the nano-scale. However, new therapeutic products, based on responsive nanomaterials, such as the ultradeformable, stress-sensitive Transfersome vesicles, are under development and already approved for human use in some countries. 10. THE

PROGRESSION OF NANOTECHNOLOGY

Why now? If it seems that nanotechnology has begun to blossom in the last ten years, this is largely due to the development of new instruments that allow researchers to observe and manipulate matter at the nanolevel. Technologies such as scanning tunneling microscopy, magnetic force microscopy, and electron microscopy allow scientists to observe events at the atomic level. At the same time, economic pressures in the electronics industry have forced the development of new lithographic techniques that continue the steady reduction in feature size and cost. One leader in nanotechnology policy has identified four distinct generations in the development of nanotechnology products, to which we can add a possible fifth: Passive Nanostructures (2000-2005) During the first period products will take advantage of the passive properties of nanomaterials, including nanotubes and nanolayers. For example, titanium dioxide is often used in sunscreens because it absorbs and reflects ultraviolet light. When broken down into nanoparticles it becomes transparent to visible light, eliminating the white cream appearance associated with traditional sunscreens. Carbon nanotubes are much stronger than steel but only a fraction of the weight. Tennis rackets containing them promise to deliver greater stiffness without additional weight. As a third example, yarn that is coated with a nanolayer of material can be woven into stain-resistant clothing. Each of these products takes advantage of the unique property of a material when it is manufactured at a nanoscale. However, in each case the nanomaterial itself remains static once it is encapsulated into the product.

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Active Nanostructures (2005-2010) Active nanostructures change their state during use, responding in predicable ways to the environment around them. Nanoparticles might seek out cancer cells and then release an attached drug. A nanoelectromechancial device embedded into construction material could sense when the material is under strain and release an epoxy that repairs any rupture. Or a layer of nanomaterial might respond to the presence of sunlight by emitting an electrical charge to power an appliance. Products in this phase require a greater understanding of how the structure of a nanomaterial determines its properties and a corresponding ability to design unique materials. They also raise more advanced manufacturing and deployment challenges. Systems of Nanosystems (2010-2015) In this stage assemblies of nanotools work together to achieve a final goal. A key challenge is to get the main components to work together within a network, possibly exchanging information in the process. Proteins or viruses might assemble small batteries. Nanostructures could self-assemble into a lattice on which bone or other tissues could grow. Smart dust strewn over an area could sense the presence of human beings and communicate their location. Small nanoelectromechancial devices could search out cancer cells and turn off their reproductive capacity. At this stage significant advancements in robotics, biotechnology, and new generation information technology will begin to appear in products. Molecular Nanosystems (2015-2020) This stage involves the intelligent design of molecular and atomic devices, leading to “unprecedented understanding and control over the basic building blocks of all natural and man-made things.” Although the line between this stage and the last blurs, what seems to distinguish products introduced here is that matter is crafted at the molecular and even atomic 12

level to take advantage of the specific nanoscale properties of different elements. Research will occur on the interaction between light and matter, the machine-human interface, and atomic manipulation to design molecules. Among the examples that Dr. Roco foresees are “multifunctional molecules, catalysts for synthesis and controlling of engineered nanostructures, subcellular interventions, and biomimetics for complex system dynamics and control.” Since the path from initial discovery to product application takes 10-12 years, the initial scientific foundations for these technologies are already starting to emerge from laboratories. At this stage a single product will integrate a wide variety of capacities including independent power generation, information processing and communication, and mechanical operation. Its manufacture implies the ability to rearrange the basic building blocks of matter and life to accomplish specific purposes. Nanoproducts regularly applied to a field might search out and transform hazardous materials and mix a specified amount of oxygen into the soil. Nanodevices could roam the body, fixing the DNA of damaged cells, monitoring vital conditions and displaying data in a readable form on skin cells in a form similar to a tattoo. Computers might operate by reading the brain waves of the operator. The Singularity (2020 and beyond) Every exponential curve eventually reaches a point where the growth rate becomes almost infinite. This point is often called the Singularity. If technology continues to advance at exponential rates, what happens after 2020? Technology is likely to continue, but at this stage some observers forecast a period at which scientific advances aggressively assume their own momentum and accelerate at unprecedented levels, enabling products that today seem like science fiction. Beyond the Singularity, human society is incomparably different from what it is today. Several assumptions seem to drive predictions of a Singularity. The first is that continued material demands and competitive pressures will continue to drive technology forward. Second, at some point artificial intelligence advances to a point where computers enhance and accelerate scientific discovery and technological change. In other words, intelligent machines start to produce discoveries that are too complex for humans. Finally, there is an assumption that solutions to most of today’s problems including material scarcity, human health, and environmental degradation can be solved by technology, if not by us, then by the computers we eventually develop. 11. HOW NANO TECHNOLOGY WILL CHANGE THE WORLD: (a). First Bricks Then The Building : Before nanotechnology can become anything other than a very impressive computer simulation, nanotechnologists are inventing an assembler, a few-atoms-large nanomachine that can custom-build matter. Engineers at Cornell and Stanford, as well as at Zyvex (the self- described "first molecular nanotechnology development company") are working to create such assemblers right now. The first products will most likely be superstrong nanoscale building materials, such as the Bucky tubes . Bucky tubes are chicken-wire-shapedtubes made from geodesic dome-shaped carbon molecules . These tubes are essentially nanometer-sized graphite fibers, and their strength is 100 to 150 times that of steel at less than one-fourth the 13

weight. With Bucky tubes we can build super roller coasters that drop you from 14,000 feet or we could take tram rides through the Himalayas. The key to manufacturing with assemblers on a large scale is self-replication. One nanosized robot making wood one nano-sized piece at a time would be painfully slow. But if these assemblers could replicate themselves, we could have trillions of assemblers all manufacturing in unison. Then there would be no limit to the kinds of things we could create. "Not only our manufacturing process will be transformed, but our concept of labor. Consumer goods will become plentiful, inexpensive, smart, and durable". (b).The Ways That Molecular Nanotechnology could Change our lives:

(b.1)Manufacturing and Industry: Nanotechnology will render the traditional manufacturing process Obsolete. For example, we'd no longer have a steel mill Outfitted with enormous, expensive machinery, running on fossi fuels and employing hundreds of human workers; instead we'd have a nanofactory with trillions of nanobots synthesizing steel, molecule by molecule. Bill Spence believes that all industry would disappear except software engineering and design. We'd simply design, engineer, and do a molecular model of any product we wanted, and then software could tell a nanobot how to make it.

(b.2).Use of Natural Resources: Rather than clear-cutting forests to make paper, we'd have assemblers synthesizing paper. Rather than using oil for energy, we'd have molecule-sized solar cells mixed into road pavement a few hundred Famine would be obliterated, as food could be synthesized easily and cheaply with a microwave-sized nanobox that pulls the raw materials (mostly carbon) from the air or the soil. And by using nanobots as cleaning machines that break down pollutants, we would be able to counteract the damage we've done to the earthsince the industrial revolution.

(b.3).Medicine: Nanotechnology could also mean the end of disease as we know it. If you caught a cold or contracted AIDS, you'd just drink a teaspoon of liquid that contained an army of molecule-sized nanobots programmed to enter your body's cells and fight viruses. If a genetic disease ran in yourfamily, you'd ingest nanobots that would burrow into your DNA and repair the defective . Even traditional plastic surgery would be eliminated, as medical nanobots could change your eye color, alter the shape of your nose, or even give you a complete sex change without surgery. 12. WHAT

NEW OBJECTS WILL APPEAR BECAUSE OF NANOTECHNOLOGY?

Perhaps the big story -- with mature nanotechnology, any object can morph into any other imaginable object... truly a concept requiring personal exposure to fully understand the significance and possibilities, but to get a grip on the idea, consider this: The age of digital matter -- multi-purpose, programmable machines, change the software, and something completely different happens. 14

A simple can opener or a complex asphalt paver are both, single purpose machines. Ask them to clean your floor or build a radio tower and they "stare" back blankly. A computer is different, it is a multi purpose machine --one machine that can do unlimited tasks by changing software... but only in the world of bits and information. Fractal Robots are programmable machines that can do unlimited tasks in the physical world, the world of matter. Load the right software and the same "machines" can take out the garbage, paint your car, or construct an office building and later, wash that building's windows. In large groups, these devices exhibit what may be termed as macro (hold in your hand) sized "nanobots ", possessing AND performing many of the desirable features of mature nanomachines (as described in Drexler's, Engines of Creation, Unbounding the Future, Nanosystems, etc.).This is the beginning of "Digital Matter". These Robots look like "Rubic's Cubes" that can "slide" over each other on command, changing and moving in any overall shape desired for a particular task. These cubes communicate with each other and share power through simple internal induction coils, have batteries, a small computer and various kinds of internal magnetic and electric inductive motors (dependingon size) used to move over other cubes (details here). When sufficiently miniaturized (below 0.1mm) and fabricated using photolithography methods, cubes can also be programmed to assemble other cubes of smaller or larger size. This “self-assembly" is an important feature that will drop cost dramatically. The point is – if you have enough of the cubes of small enough dimension, they can slide over each other, or "morph" into any object with just about any function, one can imagine and program for such behavior. Cubes of sufficiently miniaturized size could be programmed to behave like the "T-2" Terminator Robot in the Arnold Schwartznegger movie, or a lawn chair... Just about any animate or inanimate object. Fractal Shape Shifting Robots have been in prototype for the last two years and this form of "digital matter" to hit the commercial seen very soon. In the near future, if you gaze out your window and see something vaguely resembling an amoeba constructing an office building, you'll know what "IT" is. This is not to say individual purpose objects will not be desirable... Back to cotton -although Cubes could mimic the exact appearance of a fuzzy down comforter (a blanket), if made out of cubes, it would be heavy and not have the same thermal properties. Although through a heroic engineering effort, such a "blanket" could be made to insulate and pipe gasses like acomforter and even "levitate" slightly to mimic the weight and mass, why bother when the real thing can be manufactured atom by atom, on site, at about a meter a second (depending on thermal considerations). Also, "single purpose" components of larger machines will be built to take advantage of fantastic structural properties of diamondoid-Buckytube composites for such things as thin, super strong aircraft parts. Today, using the theoretical properties of such materials, we can design an efficient, quiet, super safe personal vertical takeoff airocar. This vehicle of science fiction is probably science future.

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13. WHICH

INDUSTRIES SHOULD DISAPPEAR BECAUSE OF NANOTECHNOLOGY?:

Everything -- but software, everything will run on software, and general engineering, as it relates to this new power over matter... and the entertainment industry. Unfortunately, there will still be insurance salesmen and lawyers, although not in my solar orbiting city state. If as Drexler suggest, we can pave streets with self assembling solar cells, I would tend to avoid energy stocks. Mature nanites could mine any material from the earth, landfills or asteroids at very low cost and in great abundance. The mineral business is about to change. Traditional manufacturing will not be able to compete with assembler technology and what happens to all those jobs and the financial markets is a big, big issue that needs to be addressed now. We will have a lot of obsolete mental baggage and Programming to throw out of our heads... Traditional pursuits of money will need to be reevaluated when a personal assembler can manufacture a fleet of Porch, that run circles around todays models. As Drexler so intuitively points out, the best thing to do, is to get the whole world's society educated and understanding what will and can happen with this technology. This will help people make the transition and keep mental, and financial meltdowns to a minimum. 14. WHICH

NEW INDUSTRIES SHOULD BECAUSE OF NANOTECHNOLOGY?

APPEAR

Future generations are laughing as they read these words… Laughing at the utter inadequacy and closed imagination of this writing... So consider this a comically inadequate list. However, if they are laughing, I am satisfied and at peace, as this means we made it through the transition (although I fear it shall not be the last). Mega engineering for space habitation and transport in the Solar System will have a serious future. People will be surprised at how fast space develops, because right now, a very bright core of nano-space enthusiasts have engineering plans, awaiting thearrival of the molecular assembler. People like Forrest Bishop have wonderful plans for space transport and development, capable of being implemented in surprisingly short time frames. This is artificial life, programmed to "grow" faster than natural systems. I think Mars will be teraformed in less time than it takes to build a nuclear power plant in the later half of the good old, backward 20th century. An explosion in the arts and service industries are to be expected when no fields need to be plowed for our daily bread, similar to the explosion when agriculture became mechanized and efficient and the sons and daughters of farmers migrated to cities. This explosion will be exponentially greater. Leisure time, much more leisure time, more diversions... · What professions should disappear because of nano-technology ?

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Ditch digger, tugboat captain – most professions where humans are now used as "smart brawn", or as "the best available computer", including jet fighter pilot, truck driver, surgeon, pyramid builder, steel worker, gold miner... not that there will not be people doing these jobs, just for fun. Charming libation venders have a good future, until the A.I. We are just on the verge for finding out how frequent and varied novel situations can be. 15. NEW

ENTERTAINMENT / EXPERIENCES WHICH WILL BE POSSIBLE WITH NANOTECHNOLOGY?

Perhaps the definition of life and entertainment will become blurred, but as I have previously noted, you can have a LOT of fun with Utility Fog and a super internet. In the near term, how about designing a "roller coaster" that self assembles (traditional construction costs are not a consideration) and made of supermaterials 80-100 times as strong and much lighter than steel. That first drop can be made from 14,000 feet! The ride can last until you need the skin replaced on your face. How about a tram ride through the Himalayas? Amateur underwater archeologist could map and recover ancient treasures from the Mediterranean in personal subs bristling with sensors. Dinosaur hunters could send down microscopic probes into the Earth searching for new fossil fields, then release nanomachines to meticulously unearth finds. Zero G sports are yet to be defined. These are simple examples written by a mind stuck in this contemporary world view. The possibilities are as numerous as moves in 3-D chess. The Foresight Institute suggest we now have the question of not if the technology can be developed, but when. I agree. The this is a function of the general concept awareness in society. The media is picking up Drexler's ideas ever more quickly now. Presently, two American companies are know to be engineering several "magical" assembler dependent products right now, in anticipation of the arrival of the assembler. Who knows how many black government projects may have hundreds of millions in funding around the world. The militaraZ understands Drexler's ideas and what a weapons boon nanotechnology will be. Keep in mind ,nanotechnology is not the ultimate,nor the end of technology… is nexpico technology (trillionth of a meter)? If so, this technology would deal with "matter" on a scale 1000 times smaller and emanate from deep inside the quantum realm... What does this mean? Power and understanding over space-time to engineer super luminal flight (faster than light)? Perhaps. If so, this would probably represent only the tip of this quantum weirdness iceberg. Pico Technology may be developed with enhanced intelligence made available through nanotechnology.

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16. PROBLEMS

WITH CURRENT NANOTECHNOLOGY RESEARCH IDEAS ENERGY REQUIREMENTS:

One of the big problems not fully appreciated with current ideas in nano technology research is the energy requirements for synthesizing bulk materials and big molecules. If you wanted to build concrete for example atom by atom, then one has to seriously ask whether it is best done using ingredients used for the manufacture of concrete which is found in reasonable abundance or do we start with atoms. If we start with atoms, then every chemical bond in concrete must be synthesised bond, by bond, using chemical steps that would at best use several times that bond energy to achieve the desired effect. The result is a an energy requirement to synthesise concrete that is way beyond the energy required to make concrete from existing ingredients. For this reason, bulk materials will never be synthesised using nano technology methods. Nanotechnology contributions would be limited to making simple precursors if that is energetically feasible and low cost enzymes that speed up various chemical reactions. (A).Cross Bonding: In trying to synthesise very large molecules, like DNA, the problems with cross bonding and reactive intermediates bonding unfavourably with other molecules poses a huge risk to making perfect molecules. The work of enzymes overcome most of these difficulties. However, enzymes have to be developed that co- exist with other enzymes and other chemicals. In nature, this is achieved through millions of years of evolution where the right chemicals have been found to do the right job through natural selection pressures. Beyond that, compartmentalisation is used where chemicals cannot co-exist through their design. The compartmentalisation also requires various molecules to transport materials through membranes separating the compartments. All these operations require a huge diversity of chemicals that have to be researched and perfected so that they can co-exist with the previous set of chemicals. (B).Time Restrictions: To perfect such systems require an unreasonable amount of effort on behalf of a nano technologist to search out all combinations. It requires considerable effort even now to research just one chemical in all its glorious working detail let alone combinations of chemicals in a system. (C).Wholesale Mistakes: Nano-technologists hope to side-step many of the issues by using something the equivalent of a robot arm to perform molecular level assembly. Certainly for mass manufacturing, this is a wholesale mistake as can be proved when energy considerations are taken into account.

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(D).Reality: The idea of molecular assembly is taken from DNA synthesis where a small unit called ribosome attaches to a strand of DNA, moving along it 3 base pairs at a time to read the genetic code. The genetic code is a bit like binary code but binary codes have only two levels which are 0 and 1. The genetic code however consist of 4 different kinds of bases formed into complementary pairs, and since each of these base pairs can have 4 different values and when 3 sets of base pairs are read, there are 4^3 different levels or 64 levels that 3 base pairs can code. There are around 20 amino acids that are coded for by base pairs leaving some of the remaining 44 codes not to be used or to doubly code up existing amino acids. The amino acids are strung together to make a polypeptide chain and this polypeptide chain is the precursor for each of the different chemicals that is found in our body. The polypetides are processed into various proteins which could be anything from a nutrient to an enzyme. In all of these operations, the ribosome is the key component that translates millions of years of evolution coded into the DNA as information into actual chemicals that make up living organisms. It is too tempting and too far a leap to think that all that DNA technology could be replicated in the lab with simple robot arms to make nano- technology machines. (E).Energy Consumption: For one thing a robot arm that picks up a precursor and attaches them precisely to a growing molecule is particularly energy inefficient. You have to pick up the precursor from one place and place it an another which requires HUGE amounts of energy in relation to the actual work accomplished. (F).Biological Systems & Energy Conservation In biological system, the currency for energy is the energy carried by ATP (Adenosine Tri-Phosphate). Every time an action is required usually a molecule of ATP is involved and energy is absorbed from ATP which is then recycled. Its common for biochemists to cite reactions in terms of the number of ATP molecules consumed per reaction. So some chemicals require 1 ATP to accomplish its reactions while others including very large molecules require hundreds to thousands of ATP molecules to accomplish all its tasks. To move a ribosome 3 base pairs while its attached to a DNA requires huge numbers of ATP molecules to be consumed. But a lot of it is recovered when the final protein it makes is broken down as it gets recycled which means that overall, the process of reading DNA and making macro molecules is fairly energy efficient. Compare that scenario where a robot arm with dimensions approaching a fraction of a micron is used to synthesise molecules. Every time the arm swings around to pick a chemical and place it at the right place to synthesise an exotic chemical, it spends billions of ATP energy equivalents in doing mechanical work. As the robot arm requires computers and sensors to make them work, we are now counting into trillions of ATP energy equivalents make one chemical bond in the newly synthesised product. There is no getting away from this reality of the total energy cost in making a new materials from scratch. Nano technology using this type of universal assembler is clearly nonsense and 19

doomed to failure in all but a handful of cases where small quantities of exotic chemicals are involved. (G).Energy For Computers & Robot Arms: It does not matter how small a scale we go, if we use robot arms that have to be swung around, the energy to drive it and the energy to make its feedback system in the form of computers work would be a tremendous waste compared to making the product by bulk techniques. Many of these research proposals have their roots from work done with STEM (Scanning Tunnelling Electron Microscope) probes. They have been used to image single atoms and also to move atoms about but all in all, the realities of molecular assembly using STEMs are being escaped here. To put a few atoms in place has cost trillions upon trillions of ATP equivalent and there is no way to make savings on that energy expenditure except apparently through miniaturisation. (H).Nature's Robot Arm: By making the robot arm smaller more energy efficiency can be achieved but still you need a computer to sense and control the operation of the robot arm which means you still end up spending billions in ATP energy quivalent to make the system work. The only reason why DNA works is because the ribosome sits on the DNA and moves along three base pairs of the DNA strand to read information. The energy required to transfer information from DNA to final product is still high but the product is burned to recycle the energy which means that in total no more than a couple of hundred to a couple of thousand ATP equivalent is used up per product molecule (i.e. energy used from start to finish including pre- cursors, membrane transport etc.). That is why replication and protein synthesis in nature works. Spending and recovering energy is the reality of a biological assembly system that reads information stored in a molecule, converts the information briefly to products before recycling them to recover the energy spent. (I).Energy Of Chemical Synthesis: A man made robot arm does not recycle lost energy. So where is the justification by nanotechnologists in their claims for making food from a handful of elements at some time in the future? There is no justification for such a claim! Its far easier and better done using biological organisms!! What of making concrete and other structures with universal assembler? This again is nonsense and it is far easier done with bulk chemicals and bulk processes where minerals and starting materials are extracted efficiently from the ground in their native state and processed to yield the desired products using conventional chemical processing steps. The development of enzymes that speed up reactions is extremely useful which is best once again synthesised from chemicals that are available from the lab shelves rather than synthesised in limited quantities by a nano-assembler. Commercial realities dictate that its wiser to aim for a chemical that can be synthesised readily in the 20

lab rather than an ultra expensive exotic chemical quantities with a universal assembler.

that can only be built in small

(J).Lack Of Self Repair: Another subject not fully appreciated about the biological system is the self repair systems built in at all levels from repairing damaged DNA code to destroying molecules to remanufacture them for re-use. Small machines need self repair at all levels to cope with the high breakage rates found at the smaller scales. Nanotechnologists cannot even begin to address the question right now because they don't have any nano technology machines ready for this work to be carried out! 17. NANOTECHNOLOGY

CHALLENGES,

RISKS

AND

ETHICS The most immediate challenge in nanotechnology is that we need to learn more about materials and their properties at the nanoscale. Universities and corporations across the world are rigorously studying how atoms fit together to form larger structures. We're still learning about how quantum mechanics impact substances at the nanoscale. Because elements at the nanoscale behave differently than they do in their bulk form, there's a concern that some nanoparticles could be toxic. Some doctors worry that the nanoparticles are so small, that they could easily cross the blood-brain barrier, a membrane that protects the brain from harmful chemicals in the bloodstream. If we plan on using nanoparticles to coat everything from our clothing to our highways, we need to be sure that they won't poison us. Closely related to the knowledge barrier is the technical barrier. In order for the incredible predictions regarding nanotechnology to come true, we have to find ways to mass produce nano-size products like transistors and nanowires. While we can use nanoparticles to build things like tennis rackets and make wrinkle-free fabrics, we can't make really complex microprocessor chips with nanowires yet.

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There are some hefty social concerns about nanotechnology too. Apocalyptic Goo Nanotechnology may also allow us Eric Drexler, the man who introduced the word to create more powerful weapons, nanotechnology, presented a frightening apocalyptic vision -both lethal and non-lethal. Some self-replicating nanorobots malfunctioning, duplicating organizations are concerned that themselves a trillion times over, rapidly consuming the entire world as they pull carbon from the environment to build more we'll only get around to examining of themselves. It's called the "grey goo" scenario, where a the ethical implications of synthetic nano-size device replaces all organic material. nanotechnology in weaponry after Another scenario involves nanodevices made of organic these devices are built. They urge material wiping out the Earth -- the "green goo" scenario. scientists and politicians to examine carefully all the possibilities of nanotechnology before designing increasingly powerful weapons. If nanotechnology in medicine makes it possible for us to enhance ourselves physically, is that ethical? In theory, medical nanotechnology could make us smarter, stronger and give us other abilities ranging from rapid healing to night vision. Should we pursue such goals? Could we continue to call ourselves human, or would we become transhuman -- the next step on man's evolutionary path? Since almost every technology starts off as very expensive, would this mean we'd create two races of people -- a wealthy race of modified humans and a poorer population of unaltered people? We don't have answers to these questions, but several organizations are urging nanoscientists to consider these implications now, before it becomes too late. Not all questions involve altering the human body -- some deal with the world of finance and economics. If molecular manufacturing becomes a reality, how will that impact the world's economy? Assuming we can build anything we need with the click of a button, what happens to all the manufacturing jobs? If you can create anything using a replicator, what happens to currency? Would we move to a completely electronic economy? Would we even need money? Whether we'll actually need to answer all of these questions is a matter of debate. Many experts think that concerns like grey goo and transhumans are at best premature, and probably unnecessary. Even so, nanotechnology will definitely continue to impact us as we learn more about the enormous potential of the nanoscale.

18. THE

FUTURE OF NANOTECHNOLOGY

In the world of "Star Trek," machines called replicators can produce practically any physical object, from weapons to a steaming cup of Earl Grey tea. Long considered to be exclusively the product of science fiction, today some people believe replicators are a very real possibility. They call it molecular manufacturing, and if it ever does become a reality, it could drastically change the world.

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Atoms and molecules stick together because they have complementary shapes that lock together, or charges that attract. Just like with magnets, a positively charged atom will stick to a negatively charged atom. As millions of these atoms are pieced together by nanomachines, a specific product will begin to take shape. The goal of molecular manufacturing is to manipulate atoms individually and place them in a pattern to produce a desired structure. The first step would be to develop nanoscopic machines, called assemblers, that scientists can program to manipulate atoms and molecules at will. Rice University Professor Richard Smalley points out that it would take a single nanoscopic machine millions of years to assemble a meaningful amount of material. In order for molecular manufacturing to be practical, you would need trillions of assemblers working together simultaneously. Eric Drexler believes that assemblers could first replicate themselves, building other assemblers. Each generation would build another, resulting in exponential growth until there are enough assemblers to produce objects.

Assemblers might have moving parts like the nanogears in this concept drawing.

Trillions of assemblers and replicators could fill an area smaller than a cubic millimeter, and could still be too small for us to see with the naked eye. Assemblers and replicators could work together to automatically construct products, and could eventually replace all traditional labor methods. This could vastly decrease manufacturing costs, thereby making consumer goods plentiful, cheaper and stronger. Eventually, we could be able to replicate anything, including diamonds, water and food. Famine could be eradicated by machines that fabricate foods to feed the hungry. 23

Nanotechnology may have its biggest impact on the medical industry. Patients will drink fluids containing nanorobots programmed to attack and reconstruct the molecular structure of cancer cells and viruses. There's even speculation that nanorobots could slow or reverse the aging process, and life expectancy could increase significantly. Nanorobots could also be programmed to perform delicate surgeries -- such nanosurgeons could work at a level a thousand times more precise than the sharpest scalpel [source: International Journal of Surgery]. By working on such a small scale, a nanorobot could operate without leaving the scars that conventional surgery does. Additionally, nanorobots could change your physical appearance. They could be programmed to perform cosmetic surgery, rearranging your atoms to change your ears, nose, eye color or any other physical feature you wish to alter. Nanotechnology has the potential to have a positive effect on the environment. For instance, scientists could program airborne nanorobots to rebuild the thinning ozone layer. Nanorobots could remove contaminants from water sources and clean up oil spills. Manufacturing materials using the bottom-up method of nanotechnology also creates less pollution than conventional manufacturing processes. Our dependence on non-renewable resources would diminish with nanotechnology. Cutting down trees, mining coal or drilling for oil may no longer be necessary -- nanomachines could produce those resources. Many nanotechnology experts feel that these applications are well outside the realm of possibility, at least for the foreseeable future. They caution that the more exotic applications are only theoretical. Some worry that nanotechnology will end up like virtual reality -- in other words, the hype surrounding nanotechnology will continue to build until the limitations of the field become public knowledge, and then interest (and funding) will quickly dissipate.

19. POTENTIAL SIDE

EFFECTS:

What will happen to the global order when assemblers and automated engineering eliminate the need for most international trade? How will society change when individuals can live indefinitely? What will we do when replicating assemblers can make almost anything without human labor? What will we do when AI systems can think faster than humans? (A).The Right Tools in the Wrong Hands: As with computers, nanotechnology and programmable assemblers could become ordinary household objects. It's not too likely that the average person will get hold of and launch a nuclear weapon, but imagine a deranged white separatist launching an army of nanobots programmed to kill anyone with brown eyes or curly hair. And even if nanotechnology remains in the hands of governments, think what a Stalin or a Saddam Hussein could do. Vast armies of tiny, specialized killing machines that could be built and dispatched in a day; nano-sized surveillance devices or probes that could be implanted in the brains of people without their knowledge. The potential misuses of nanotechnology are vast. (B).Attack of the Killer Nanobots?:

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And what about the old sci-fi fear that robots will evolve greater intelligence than humans, become sentient, and take over the world? Certainly nanomachines might replicate and spread faster than we could control them. Drexler posits that a little thinking ahead could address this problem. For example, self-replicating assemblers could be programmed to compare their instruction sets an destroy any copies with the slightest deviation. That way, mutant nanobots could be contained before they did any damage. One point most fail to realize when first considering the effects of nanotechnology on population (the demise and reversal ofaging), is the same nanotechnology will open up outer space with all its unimaginable quantities of material, energy and elbowroom, with truly inexpensive access, great safety (massively redundant systems) made possible by the new economics of self replicating machinery. "The Solar System could accommodate the population of the Earth a billion times over, (living) in style." Also to be considered is the fact once nanotechnology arrives, this is not the end of discovery and technology. It is a futile endeavor... to consider how population is affected by this technology viewed with a perspective of arrival, then a flat curve, through to infinity. 20. CONCLUSION: Humanity will be faced with a powerful, accelerated social revolutions as a result of nanotechnology. In the near future, a team of scientists will succeed in constructing the first nao-sized robot capable Of self replication. Consumer goods will become plentiful, inexpensive, smart, and durable. Medicine will take a quantum leap forward. Space travel and colonization will become safe and affordable. For these and other reasons global life styles will change radically and human behavior drastically impacted.

REFERENCES: 1. 2. 3. 4. 5. 6.

www.howstuffworks.com http://en.wikipedia.org/wiki/Nanotechnology www.wisegeeks.com http://www.actionbioscience.org/ http://www.crnano.org/ http://www.pdfcoke.com/

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