• Title of the report Nano Technology• Date of submission 03/12/2018• Prepared for Hafiz sajjad• Prepared by Asim RiazTABLE OF CONTENTS1. Introduction 2. History of nanotechnology 3. Nanotechnology tools 4. Nanotechnology size concerns 5. Traditional approach 6.
Conclusion 7. ReferencesIntroduction Molecular nanotechnology or Nanotechnology is the designation given to a specific sort of Manufacturing technology to build things from the atom up, and to rearrange matter With atomic precision. In other words, we can say that nanotechnology is a three Dimensional structural control of material and devices at molecular level. The Nanoscale structures can be prepared, characterized, operated, and smooth imagined By riggings. “Nanotechnology is a tool-driven field.” Other terms, such as molecular engineering or molecular manufacturing are also often Applied when describing this emerging technology.
This technology does not yet Exist. But, scientists have recently gained the ability to observe and manipulate atoms Directly. However, this is only one small aspect of a growing array of techniques in Nanoscale science and technology. The ability to make commercial products may yet Be a few decades away. “Nanotechnology is Engineering, Not Science.” The central thesis of nanotechnology is that almost any chemically stable structure That is not specifically disallowed by the laws of physics can in fact be built. Theoretical and computational models indicate that molecular manufacturing systems Are possible — that they do not violate existing physical law.
These models also give Us a feel for what a molecular manufacturing system might look like. Melting pot of Science combining applications of physics, chemistry, biology, electronics and Computers. Nowadays, experts are planning many tools and The Nanoscale constructions can be prepared, characterized, manipulated, and even visualized The Nanoscale structures can be ready, characterized, operated, and even imagined methods that will be Wanted to transform nanotechnology from computer models into reality. Nanotechnology is often called the science of the small. It is concerned with Manipulating particles at the atomic level, usually in order to form new compounds or Make changes to existing substances. Nanotechnology is being applied to problems in Electronics, biology, genetics and a wide range of business applications. Matter is composed of small atoms that are closely bound together, making up the Molecular structure, which, in turn determines the density of the concerned material. Since different factors such as molecular density, malleability, ductility and surface Tension come into play, Nano systems have to be designed in a cost effective manner That overrides these conditions and helps to create machines capable of withstanding The vagaries of the environment.
Let us take the case of metals. Metals, solids in particular, consist of atoms held Together by strong structural forces, which enable metals to withstand high Temperatures. Depending upon the exertion of force or heat, the molecular structure Bends in a particular fashion, thereby acquiring a definite space in the form of a lattice Structure.
When the bonding is strong, the metal is able to withstand pressure. Else it Becomes brittle and finally breaks up. So, only the strongest, the hardest, the highest Melting point metals are worth considering as parts of Nano machines.2.
HISTORY OF NANOTECHNOLOGY Any advanced research carries inherent risks but nanotechnology bears a special Burden. The field’s bid for respectability is colored by the association of the word with A cabal of futurist who foresee Nano as a pathway to a techno-utopia: unparalleled Prosperity, pollution-free industry, even something resembling eternal life. In 1986-five years after IBM researchers Gerd Binnig and Heinrich Rohrer invented The scanning tunneling microscope, which garnered them the Nobel Prize-the book Engines of Creation, by K. Eric Drexler, created a sensation for its depiction of Godlike control over matter.
The book describes self-replicating Nano machines that Could produce virtually any material good, while reversing global warming, curing Disease and dramatically extending life spans. Scientists with tenured faculty positions And NSF grants ridiculed these visions, noting that their fundamental improbability Made them an absurd projection of what the future holds. But the visionary scent that has surrounded nanotechnology ever since may provide Some unforeseen benefits. To many nonscientists, Drexler’s projections for Nanotechnology straddled the border between science and fiction in a compelling way. Talk of cell-repair machines that would eliminate aging as we know it and of home Food-growing machines that could produce victuals without killing anything helped to Create a fascination with the small that genuine scientists, consciously or not, would Later use to draw attention to their work on more mundane but eminently more real Projects. Certainly labeling a research proposal “nanotechnology” has a more alluring Ring than calling it “applied mesoscale materials science.” Less directly, Drexler’s work may actually draw people into science.
His imaginings Have inspired a rich vein of science-fiction literature. As a subgenre of science Fiction-rather than a literal prediction of the future-books about Drexler Ian Nanotechnology may serve the same function as Star Trek does in stimulating a Teenager’s interest in space, a passion that sometimes leads to a career in aeronautics Or astrophysics. The danger comes when intelligent people take Drexler’s predictions at face value. Drexler Ian nanotechnology drew renewed publicity last year when a morose Bill Joy, The chief scientist of Sun Microsystems, worried in the magazine Wired about the Implications of Nano robots that could multiply uncontrollably. A spreading mass of Self-replicating robots-what Drexler has labeled “gray goo”-could pose enough of a Threat to society, he mused, that we should consider stopping development of Nanotechnology. But that suggestion diverts attention from the real Nano goo: Chemical and biological weapons.3. NANOTECHNOLOGY TOOLS What would it mean if we could inexpensively make things with every atom in the Right place? For starters, we could continue the revolution in computer hardware right Down to molecular gates and wires — something that today’s lithographic methods (Used to make computer chips) could never hope to do.
We could inexpensively make Very strong and very light materials: shatterproof diamond in precisely the shapes we Want, by the ton, and over fifty times lighter than steel of the same strength. We could make a Cadillac that weighed fifty kilograms, or a full-sized sofa you could pick up With one hand. We could make surgical instruments of such precision and deftness That they could operate on the cells and even molecules from which we are made — Something well beyond today’s medical technology. The list goes on — almost any Manufactured product could be improved, often by orders of magnitude. 3.1 THE ADVANTAGES OF POSITIONAL CONTROL One of the basic principles of nanotechnology is positional control. At the Macroscopic scale, the idea that we can hold parts in our hands and assemble them by Properly positioning them with respect to each other goes back to prehistory: At the molecular scale, the idea of holding and positioning molecules is new and Almost shocking. However, as long ago as 1959 Richard Feynman, the Nobel prize Winning physicist, said that nothing in the laws of physics prevented us from Arranging atoms the way we want: “.
..it is something, in principle, that can be done; But in practice, it has not been done because we are too big.
” Before discussing the advantages of positional control at the molecular scale, it’s Helpful to look at some of the methods that have been developed by chemists — Methods that don’t use positional control, but still let chemists synthesize a Remarkably wide range of molecules and molecular structures. 3.2 SELF ASSEMBLY The ability of chemists to synthesize what they want by stirring things together is Truly remarkable.
Imagine building a radio by putting all the parts in a bag, shaking, And pulling out the radio — fully assembled and ready to work! Self-assembly — the Art and science of arranging conditions so that the parts themselves spontaneously Assemble into the desired structure — is a well-established and powerful method of Synthesizing complex molecular structures.3.3 POSITIONAL DEVICES AND POSITIONALLY CONTROLLED REACTIONS While self-assembly is a path to nanotechnology, by itself it would be hard pressed to Make the very wide range of products promised by nanotechnology. We don’t know How to self-assemble shatterproof diamond, for example. During self-assembly the Parts bounce around and bump into each other in all kinds of ways, and if they stick Together when we don’t want them to stick together, we’ll get unwanted globs of Random parts. Many types of parts have this problem, so self-assembly won’t work for Them.
To make diamond, it seems as though we need to use indiscriminately sticky Parts (such as radicals, carbines and the like). These parts can’t be allowed to Randomly bump into each other (or much of anything else, for that matter) because They’d stick together when we didn’t want them to stick together and form messy blobs Instead of precise molecular machines.3.4 STIFFNESS Molecular arms will be buffeted by something we don’t worry about at the Macroscopic scale: thermal noise. This makes molecular-scale objects wiggle and Jiggle, just as Brownian motion makes small dust particles bounce around at random.
The critical property we need here is stiffness. Stiffness is a measure of how far Something moves when you push on it. If it moves a lot when you push on it a little, It’s not very stiff. If it doesn’t budge when you push hard, it’s very stiff. 3.
5 SCANNING TUNNELING MICROSCOPE (STM) The STM is a device that can position a tip to atomic precision near a surface and can Move it around. The scanning tunneling microscope is conceptually quite simple. It Uses a sharp, electrically conductive needle to scan a surface. The position of the tipoff the needle is controlled to within 0.1 angstrom (less than the radius of a hydrogen Atom) using a voltage-controlled piezoelectric drive.
When the tip is within a few Angstroms of the surface and a small voltage is applied to the needle, a tunneling Current flows from the tip to the surface. This tunneling current is then detected and Amplified, and can be used to map the shape of the surface, such as a blind man Tapping in front of him with his cane, we can tell that the tip is approaching the Surface and so can “feel” the outlines of the surface in front of us.4. NANOTECHNOLOGY SIZE CONCERNS 4.1 MEMS: MICRO INFORMATION SEEKERS Micro-electromechanical system (MEMS) combines computers with tiny mechanical Devices such as sensors, valves, gears, and actuators embedded in semiconductor Chips.
These elements are embedded in the mainframe of the system for carrying out The bigger task. As the elements are capable of carrying out varying tasks, they are Usually reoffered to as ‘smart matter’. Nanotechnology is often confused with related fields such as Microelectromechanical Systems (MEMS) and molecular electronics. Table below, illustrates the most basic Differences among these various efforts, which do have some overlap. In the case of MEMS, it helps to remember that while the two technologies differ by a factor of About 1000 in linear dimension, this translates to a factor of a billion in volume—very Different indeed. Also, as MEMS researchers point out, MEMS is not a goal but a Working technology, rapidly growing into a major industry. 5 THE TRADITIONAL APPROACH Today, electronic devices, sensors, motors, and many other items are fabricated using A top down approach.
Today’s computer chips are made using photolithography, a Process that uses light and chemicals to etch lines into silicon wafers. The process Requires vacuum chambers, powerful lasers and hazardous chemicals, which is why State-of-the-art chip factories tend to be billion-dollar facilities. As device features Have become finer, the number of devices that can be crammed onto a chip has been Doubling every 18 to 24 months. But chipmakers will be hard-pressed to extend this miniaturization trend for another Decade.
As device features shrink into the low-nanometer range, the chips will not be Able to perform as reliably. Moreover, the cost of constructing new fabrication lines For each new generation of chips will become prohibitive. 5.1 THE NANOTECHNOLOGY APPROACH Nanotechnology promises an inexpensive bottom up alternative in which electronic Or other devices will be assembled from simpler components such as molecules and Other Nano-structures. This approach is similar to the one nature uses to construct Complex biological architectures. Nano-products will be smarter than the traditional Devices as devices operate at the most fundamental level here atoms and Molecules, instead of bits and bytes.
Suitors. Just as today’s computers are showing up in More and more products, Nano-computers and Nano-defined materials will be Able to improve just about any object we use, including our own bodies.6. Conclusion The work in nanotechnology is being carried out not just on the materials of the future, but also the tools that will allow us to use these ingredients to create products. Experimental work has already resulted in the production of scanning tunneling microscope, molecular tweezers, and logic devices.
Theoretical work in the construction of nano-computers is progressing as well. Taking all of this into account, it is clear that the technology is feasible. Nanotechnology is expected to have a profound impact on our economy and society in the 21st century, from the development of better, faster, stronger, smaller, and cheaper systems. Nanotechnology provides a far more powerful capability. We cannot make powerful computers, defense, environment and medicine, but also in a higher standard of living for everyone on the planet. Nanotechnology- the science is good, the engineering is feasible, the paths of approach are many, the consequences are revolutionary-times-revolutionary, and the schedule is: in our lifetimes.
6. REFERENCES www.zyvex.com www.foresight.org www.nanoelectronicsplanet.com www.nanotechnology.com Information technology – June 2018
