Smart Materials

Smart Materials or we can say "Intelligent" material is capable of spontaneously changing its physical properties (notably its shape, chemical, structural, viscosity etc..) in response to natural or provoked excitation. These can come from outside or inside the smart materials: temperature variations, mechanical constraints, electric, light response, piezoelectric or magnetic fields. This generation smart pigments and dyes is opposed to conventional materials, which are inert by definition, and whose properties always remain the same regardless of the stresses to which the material is subjected. Smart materials able to adapt its response, to signal a modification in the environment and, in some cases, to take corrective action it can behave like a sensor, an actuator or like a processor. 

One of the most important families of smart products is the X-chrome materials. These smart materials have the ability to change color in response of an external excitation: temperature, light, pressure, humidity, etc. The color of these materials becomes "adaptive/interactive" with reversible, irreversible or memory effect properties. It is thus possible to detect by a simple change of color structural weaknesses in the coating, a temperature threshold exceeded to signal the risk of burning. 

Application of Smart Material 

Intelligent materials are growing, as is the field of applications in industry, housing, medicine, biology and leisure. This is a real revolution on the scale of materials that will rapidly change our daily lives. Some smart materials are, for example, sensitive to glucose for controlled release of insulin, or in response to an electric or magnetic fields for drug delivery. In the field of construction and energy improvement, some ionic polymers allow access to intelligent glazing. A smart glass is able to become opaque or transparent in a few seconds for better light management in a building. 

Engine / Gearbox

The engine and transmission of a modern Formula One car are some of the most highly stressed pieces of machinery on the planet, and the competition to have the most power on the grid is still intense.

Traditionally, the development of racing engines has always held to the dictum of the great automotive engineer Ferdinand Porsche that the perfect race car crosses the finish line in first place and then falls to pieces. Although this is no longer strictly true - regulations now require engines to last more than one race weekend - designing modern Formula One engines remains a balancing act between the power that can be extracted and the need for just enough durability.

Engine power outputs in Formula One racing are also a fascinating insight into how far the sport has moved on. In the 1950s Formula One cars were managing specific power outputs of around 100 bhp / litre (about what a modern 'performance' road car can manage now). That figure rose steadily until the arrival of the 'turbo age' of 1.5 litre turbo engines, some of which were producing anything up to 750 bhp / litre. Then, once the sport returned to normal aspiration in 1989 that figure fell back, before steadily rising again. The 'power battle' of the last few years saw outputs creep back towards the 1000 bhp barrier, some teams producing more than 300 bhp / litre in 2005, the final year of 3 litre V10 engines. Since 2006, the regulations have required the use of 2.4 litre V8 engines, with power outputs falling around 20 percent.

Revving to 19,000 RPM, a modern Formula One engine will consume a phenomenal 650 litres of air every second, with race fuel consumption typically around the 75 l/100 km (4 mpg) mark. Revving at such massive speeds equates to an accelerative force on the pistons of nearly 9000 times gravity. Unsurprisingly, engine-related failures remain one of the most common causes of retirements in races.

Modern Formula One engines owe little except their fundamental design of cylinders, pistons and valves to road-car engines. The engine is a stressed component within the car, bolting to the carbon fibre 'tub' and having the transmission and rear suspension bolted to it in turn. Therefore it has to be enormously strong. A conflicting demand is that it should be light, compact and with its mass in as low a position as possible, to help reduce the car's centre of gravity and to enable the height of rear bodywork to be minimised.

The gearboxes of modern Formula One cars are now highly automated with drivers selecting gears via paddles fitted behind the steering wheel. The 'sequential' gearboxes used are very similar in principle to those of motorbikes, allowing gear changes to be made far faster than with the traditional ‘H’ gate selector, with the gearbox selectors operated electrically. Despite such high levels of technology, fully automatic transmission systems, and gearbox-related wizardry such as launch control, are illegal - a measure designed to keep costs down and place more emphasis on driver skill. Transmissions - most teams run seven-speed units - bolt directly to the back of the engine.

Mindful of the massive cost of these ultra high-tech powertrains, the FIA introduced new regulations in 2005 limiting each car to one engine per two Grand Prix weekends, with ten-place grid penalties for those breaking the rule. From 2008, a similar policy was applied to gearboxes, each having to last four race weekends. On top of these measures, a freeze on engine development imposed at the end of the 2006 season means teams are unable to alter the fundamentals of their engines’ design until at least 2010.

A Combined Upper Bound and Fnite Element Model for Prediction of Velocity and Temperature Fields During Hot Rolling Process

Controlling strain distribution during rolling of metals is a significant task in designing a proper rolling layout. There are several models and approaches for prediction of strain, strain rate and temperature distributions during and after rolling operations. For instance, plane strain rolling process has been considered by Takuda et al. They have used an upper bound method to calculate roll force and required energy for cold rolling of metals under plane strain conditions. In another work, an upper bound method employing a spherical velocity field has been proposed to analyze hot rolling of austenitic steel sheets. Marques and Martins have used a dual stream function coupled with an upper bound model to determine required energy in three-dimensional rolling operations. Chung et al. have predicted velocity field during steady-state hot deformation operations including hot strip rolling of metals, by combining of stream-line coordinates and a two-dimensional finite difference method. Chen et al. have calculated temperature and strain fields by a coupled finite element method (FEM) and FDM codes. Nepershin has modeled metal flow in plane-strain rolling process assuming fully sticking friction conditions. A combined finite element-boundary element approach has been used to analyze the cold plane strain rolling process . the FEM has been used to determine the velocity field within the metal being deformed while the boundary element method has been employed for the determination of work-roll deformation. Bar rolling operations have been investigated using a steady-state rigid–viscoplastic finite element approach by Kim et al. There are also other published researches concerning mathematical modelling of cold or hot rolling of metals, while numerical techniques particularly the finite element analysis have been utilized for determining the deformation behavior in rolling metal . Although several published researches on the modelling of rolling can be found in the literature; however, because of the complex geometry of the deformation zone and the nonlinear behavior of metal particularly during hot rolling, more accurate models with relatively shorter run-time duration is still necessary in order to analyze the process during on-line rolling practice. a new approach is developed to propose an admissible velocity field in hot strip rolling process. This approach is based on the principle of volume constancy and a combination of upper bound method and the finite element analysis. A velocity field is first proposed, utilizing the principle of volume constancy, and then the velocity field is modified using the upper bound theorem. At the same time a thermal-finite element analysis is coupled with the deformation model to predict flow stress of deforming material as a function of temperature as well as to determine temperature distribution within the metal. The main point of the proposed model is its relatively short run-time duration in comparison with that inregular fully finite element codes.

Nanotechnology applications in future medicine

First let me explain what is nanotechnology is, It is a technology which deals with matter in atomic scale and are capable of creating small machines which can work in molecular level ( nanobots are not yet created ) and a nanometer is a unit of spatial measurement that is 10^-9 meter, or one billionth of a meter. It is commonly used in nanotechnology. Now It is computer / IT revolution an it had itz fair contribution in the field of Medical research but In coming decades we will see revolution in nanotechnology, quantum physics, human genome research and stem cell research, we will see things which we have never ever imagined before, and nanotechnology will be playing its big part in this never ever imagined health and Medical science revolution.

Regenerating Tissues with the help of nanobots

Americans are spending a lot for anti ageing medicines, in coming years nanotechnology will be assisting the new anti ageing drive . What i can feel is nanotechnology can create nanobots that can be injected into our body and these nanobots will be capable of repairing damaged and old tissues. Well it sounds bit weird ! dont worry we all will get used to it if after few decades !

Nanobots assigned with Mission

Nanometres can send deep inside our body to seek and destroy infected tissue parts and blocked arteries and seek and destroy and eliminate deadly HIV viruses from human body.

Nanotechnology for super human powers !

Imagine a human being who can run 100 miles without getting tired , a man/ woman powerful enough to run as fast as 90 miles per second !These things are can be possible with nanotechnology, nanobots fused with quantum computers will be intelligent enough to alter chemicals in our body which can manipulate our functions to convert ourself into powerful human !

Some conservative people may object these nano ideas but later they will get used to it, during earlier days conservatives objected discoveries made by scientists like Copernicans etc.

These days lot of scientific research are undergoing in universities around the world and every month we are reading about new nano discoveries

Nano tech aid for repairing nurons

New research in nano medicine is moving close towards offering scientists a new way for treating and curing neuro degenerative diseases such as Alzheimer’s disease and Parkinson’s disease.

Research team of University of Arkansas used magnetic nano tubes on nerves and nurons.Due to their structure and properties, magnetic nano tubes are among the most promising candidates of multifunctional nano materials for clinical diagnostic and therapeutic applications.

Research team worked on rats found that they were able to trigger cells called PC12 cells to differentiate into neurons by using nerve growth factor-incorporated magnetic nano tubes. They say that the findings suggest that magnetic nano tubes can be used to deliver nerve growth factor in order restore or repair damaged nerve cells.

Blood steam a natural highway for nanobots

Human body is having a network of blood streams that connects every part of our body (capillaries and arteries) this is a potential pathway for nanobots that can swim through human body to other for completing their assigned mission.

Wifi Guided nanobots

Wireless technology can be used for guiding nanobots through human body and to monitor their works. one thing scientists have to make sure before making such a system is to take care of the radiation aspects of wireless technology, it have to be safe for our human body.

Magnetic Fields for mobilizing nanobots

Magnetic fields can be used to navigate nanobots from one part of body to another; the risk factor is less compared to wireless radiations.

How can nanobots move?

Nanobots can also be called as nano doctors who can get into human body and fix the faults but the question that we are facing is how can we send intelligent nanobot into human system?

Making biologically friendly nanobots (that won’t cause danger to our human body) is an important for creating medical nanobots for health care use and other task is to mobilize them towards every corner or our body.
Scientist’s are working hard on this dream project

Nanobots can also be called as nano doctors who can get into human body and fix the faults but the question that we are facing is how can we send intelligent nanobot into human system?

Making biologically friendly nanobots (that won’t cause danger to our human body) is an important for creating medical nanobots for health care use and other task is to mobilize them towards every corner or our body.
Scientist’s are working hard on this dream project

Nanotechnology - A Boon For Medical Science

Nanotechnology, or more affectionately nicknamed as nanotechnology, is a field of research that deals with controlling matter on an atomic or molecular level. This has multiple applications that range anywhere from electronics, to energy production, to engineering, to physics, and even to medicine. In the field of medicine alone, nanotechnology is giving rise to tools and possible applications that are now being streamlined to focus on finding and eradicating cancer cells. This is a particularly timely issue because cancer is now the foremost killing disease of the modern times. As humankind evolves into the new millennia, it seems that cancer cells are evolving as well. As such, there are still no known medicines or medical procedures that can prevent or cure the occurrence of any type of cancer.

Cancer, or any disease for that matter, begins and ends with the tiniest life force within the human body. These are the living cells that carry out the multiple complex functions necessary for life. Unfortunately, with today’s tools for diagnosis and surgical procedures, there is always the possibility that: damaged, infected and disease-carrying cells are overlooked (and thereby not eradicated by the treatment); and that the surgical procedure might actually do more damage as opposed to letting the disease run its course. It is not uncommon for cancer cells to metastasize to other organs in the body after removing the cancer afflicted part – even with aggressive chemotherapy. It is also not uncommon to hear patients dying from the surgical procedures or surgery patients suffering from the complications of the post operative treatments.

With nanotechnology, medicine has a fighting chance against cancer cells by producing diagnostic tools that can pinpoint the occurrence of cancerous growths as they happen; and by removing these in the cellular level that the afflicted body does not even have to be surgically opened. Nanotech has paved the way for various possibilities in diagnosis, cure and prevention of all possible diseases. Most of these are still a few technology tweaks along the way. However, the point is: the potential is now here and what may have been sheer impossibilities a good 50 years back are now becoming real by the minute. Right now, all eyes are focused on cancer research.

Cancer research with nanotechnology is particularly useful when it comes to the development and construction of smaller but more efficient cancer detection gadgets that can be easily replicated with the right technology. This means that formerly expensive diagnostic tools for cancer detection can now be made at more economical rates. Complex molecular machines can also be started on and developed further to help with correct and early disease diagnosis. One possibility that a lot of nanotechnology researchers are trying to develop are the molecular computers that not only works as a diagnostic tool but can be used as a search-and-destroy “operative” that can eradicate cancer cells on a cellular level. This is a proposed alternative to the various cocktails of medications and the series of medical procedures that one cancer patient has to endure just to slow down the process of cancer growth.

Electron beam lithography

To obtain resolutions better than the few μm of photolithography it is necessary to use either X-ray lithography or electron beam lithography. Here we give a brief overview of the latter technique. After development of the resist one can choose to etch the exposed part of the wafer. Acid will typically not etch the polymer photoresist but only the substrate, so etching will carve out the design defined by the mask. The shape of the etching depends on the acid and the substrate. It can be isotropic and have the same etch rate in all spatial directions, or it can by anisotropic with a very large etch rate in some specific directions. One can choose the etching process that is most suitable for the design. Metal deposition followed by lift-off is another core technique. Here a thin layer of metal (less than 500 nm) is deposited by evaporation technique on the substrate after de veloping the resist. At the exposed places the metal is deposited directly on the substrate, and elsewhere the metal is residing on top of the remaining photoresist. After the metal deposition the substrate is rinsed in a chemical that dissolves the photoresist and there by lift-off the metal residing on it. As a result a thin layer of metal is left on the surface of the wafer in the pattern defined by the photography mask. The above mentioned process steps can be repeated many times with different masks

and very complicated devices may be fabricated that way.

Electron beam lithography is based on a electron beam microscope, in which a focused beam of fast electrons are directed towards a resist-covered substrate. No mask is involved since the position of the electron beam can be controlled directly from a computer through electromagnetic lenses and deflectors. The electrons are produced with an electron gun, either by thermal emission from hot tungsten filament or by cold field emission. The emitted electrons are then accelerated by electrodes with a potential U ≈ 10 kV and the beam is focused by magnetic lenses and steered by electromagnetic deflectors. the electron is both a particle and a wave. The wavelength λ of an electron is given in terms by the momentum p of the electron and Planck’s constant h by the de Broglie relation Eq. λ = h/p. In the electron beam microscope the electron acquires a kinetic energy given by the acceleration voltage U as 1/2mv² = eU, where m and −e is the mass and charge of the electron, respectively. Since p = mv the expression for the wavelength λ becomes

λ = h/ √2meU

which for a standard potential of 10 kV yields λ = 0.012 nm .However, the resolution of an electron beam microscope is not given by λ. First of all, one can not focus the electron beam on such a small length scale. A typical beam spot size is around 0.1 nm. But more importantly are the scattering processes of the electrons inside the resist and the substrate. As illustrated by the computer simulation the backscattering of the electrons implies that an area much broader area is exposed to electrons than the area of the incoming electrons. This results in an increase of the resolution. It turns out that in practice it is difficult to get below a minimum linewidth of 10 nm. Electron beam lithography is still the technique with the best resolution for lithography. A major drawback of the method is the long expose time required to cover an entire wafer with patterns. The exposure time texp is inversely proportional to the current I in the electron beam and proportional to the clearing dose D (required charge per area) and the exposed area A,

texp = DA I I

In photolithography the entire wafer is exposed in one flash, like parallel processing, whereas in electron beam lithography it is necessary to write one pattern after the other in serial processing. For mass production electron beam lithography is therefore mainly used to fabricate masks for photolithography .

Photolithography

Almost all top-down manufacturing involves one or more photolithography fabricationsteps, so we give a brief outline of this technique here. From a lightsource light is directed through a mask carrying the circuit design down onto the substrate wafer covered with a photo-sensitive film, denoted the photoresist. Depending on the local photo-exposure defined by the photolithographic mask the photoresist can be partly removed by a chemical developer leaving well-defined parts of the substrate wafer exposed to etching or metal deposition. The substrate wafer is typically a very pure silicon disk with a thickness around 500 μm and diameter of 100 mm (for historic reasons denoted a 4 inch wafer). Wafers of different purities are purchased at various manufacturers. The photolithographic mask contains (part of) the design of the microsystem that is to be fabricated. This design is created using computer-aided design (CAD) software. Once completed the computer file containing the design is sent to a company producing the mask. At the company the design is transferred to a glass plate covered with a thin but non-transparent layer of chromium. The transfer process is normally based on either the relatively cheap and fast laser writing with a resolution of approximately 1.5 μm and a delivery time of around two weeks, or the expensive and rather slow electron beam writing with a resolution of 0.2 μm and a delivery time of several months. The photo exposure is typically performed using the 356 nm UV line from a mercury lamp, but to achieve the line widths of sub 100 nm mentioned in Sec. 1.1 an extreme UV source or even an X-ray source is needed. To achieve the best resolution must minimize note only the wavelength λ of the exposure light, but also the distance d between the photolithographic mask and the photoresist-covered substrate wafer, and the thickness t of the photoresist layer. The minimum line width wmin is given by the approximate expression

wmin = 3 /2 ( λ(d + t). ) ^½

If d = 0 nm the mask is touching the photo-resist. This situation, denoted contact printing,improves the resolution but wears down the mask. If d > 0 nm, a case denoted proximity printing, the resolution is pourer but the mask may last longer. It is difficult to obtain wmin < 2 μm using standard UV photolithography. The photoresist is a typically a melted and thus fluid polymer that is put on the substrate wafer, which then is rotated at more than 1000 rounds per minute to ensure an even and thin layer of resist spreading on the wafer. The photoresists carry exotic names like SU-8, PMMA, AZ4562 and Kodak 747. The solubility of the resists is proportional to the square of the molecular weight of the polymer. The photo-processes in a polymer photoresist will either cut the polymer chains in small pieces (chain scission) and thus lower the molecular weight, or they will induces cross-linking between the polymer chains and thus increase the molecular weight. The first type of resists is denoted the positive tone photoresists, they will be removed where they have been exposed to light. The second type is denoted the negative tone photoresists, they will remain where they have been exposed to light.

Clean room facilities

The small geometrical features on a microchip necessitates the use of clean room facilities during the critical fabrication steps. Each cubic meter of air in ordinary laboratories may contain more than 107 particles with diameters larger than 500 nm. To avoid a huge flux of these ”large” particles down on the chips containing micro and nanostructures, micro and nanofabrication laboratories are placed in so-called clean rooms equipped with high-efficiency particulate air (HEPA) filtering system. Such systems can retain nearly all particles with diameters down to 300 nm. Clean rooms are classified according to the maximum number of particles per cubic foot larger than 500 nm. Usually a class-1000 or class-100 clean room is sufficient for microfabrication.The low particle concentration is ensured by keeping the air pressure inside the clean room slightly higher than the surroundings, and by combining the HEPA filter systemwith a laminar air flow system in the critical areas of the clean room. The latter system let the clean air enter from the perforated ceiling in a laminar flow and leave through the perforated floor. Moreover, all personnel in the clean room must be wearing a special suit covering the whole body to minimize the surprisingly huge emission of small particles from each person. The air flow inside the DANCHIP clean room is about 1.3x 10⁵ m³ h⁻¹, most of which is recirculated particle-free air from the clean room itself. However, since the exhaust air from equipment and fume hoods is not recirculated, there is in intake of fresh air of 0.3 x10⁵ m³ h⁻¹.

MICROFABRICATION AND MOORE’S LAW

Microfabrication and Moore’s law

The top-down approach to microelectronics seems to be governed by exponential time dependence. I 1965, when the most advanced integrated circuit contained only 64 transistors, Gordon E. Moore, Director of Fairchild Semiconductor Division, was the first to note this exponential behavior in his famous paper Cramming more components onto integrated circuits [Electronics, 38, No. 8, April 19 (1965)]: ”When unit cost is falling as the number of components per circuit rises, by 1975 economics may dictate squeezing as many as 65,000 components on a single silicon chip”. He observed a doubling of the number of transistors per circuit every year, a law that has become known as Moore’s law. Today there exist many other versions of Moore’s law. It concerns the exponential decrease in the length of the gate electrode in standard CMOS transistors, and relates to the previous quoted values of 90 nm in 2003 and 65 nm in 2005. Naturally, there will be physical limitations to the exponential behavior expressed in Moore’s law, see Exercise 1.1. However, also economic barriers play a major if not the decisive role in ending Moore’s law developments. The price for constructing microprocessor fabrication units also rises exponentially for each generation of microchips.

Moore’s law in the form of the original graph from 1965 suggesting a doubling of the number of components per microchip each year. (b) For the past 30 years Moore’s law has been obeyed by the number of transistors in Intel processors and DRAM chips, however only with a doubling time of 18 months. A result extremely powerful computers and efficient communication systems have emerged with a subsequent profound change in the daily lives of all of us. A modern computer chip contains more than 10 million transistors, and the smallest wire width are incredibly small, now entering the sub 100 nm range. Just as the American microprocessor manufacturer, Intel, at the end of 2003 shipped its first high-volume 90 nm line width production to the market, the company announced that it expects to ramp its new 65 nm process in 2005 in the production of static RAM chips.1 Nanotechnology with active components is now part of ordinary consumer products. Conventional microtechnology is a top-down technology. This means that the microstructures are fabricated by manipulating a large piece of material, typically a silicon crystal, using processes like lithography, etching, and metallization. However, such an approach is not the only possibility. There is another remarkable consequence of the development of micro and nanotechnology.

Since the mid-1980’ies a number of very advanced instruments for observation and manipulation of individual atoms and molecules have been invented. Most notable are the atomic force microscope (AFM) and the scanning tunnel microscope (STM) that will be treated later in the lecture notes. These instruments have had en enormous impact on fundamental science as the key elements in numerous discoveries. The instrumentshave also boosted a new approach to technology denoted bottom-up, where instead of making small structure out over large structures, the small structures are made directly by assembling of molecules and atoms.

Top-down micro and nanotechnology

Top-down micro and nanotechnology

Nanotechnology deals with natural and artificial structures on the nanometer scale, i.e.

in the range from 1 μm down to 10 ˚A. One nanometer, 1 nm = 10⁻⁹ m, is roughly the

distance from one end to the other of a line of five neighboring atoms in an ordinary solid. The nanometer scale can also be illustrated as in Fig. 1.1: if the size of a soccer ball (similar to 30 cm = 3 x 10⁻¹ m) is reduced 10.000 times we reach the width of a thin human hair (similar to 30 μm = 3x10⁻⁵ m). If we reduce the size of the hair with the same factor, we reach the width of a carbon nanotube (similar to 3 nm=3 x10⁻⁹ m).

It is quite remarkable, and very exciting indeed, that we today have a technology that

involves manipulation of the ultimate building blocks of ordinary matter: single atoms

and molecules. Nanotechnology owes it existence to the astonishing development within the field of micro electronics. Since the invention of the integrated circuit nearly half a century ago in 1958, there has been an exponential growth in the number of transistors per micro chip and an associated decrease in the smallest width of the wires in the electronic circuits.

EXQUISITE DESIGN

Mechanical engineering concepts also come into play in designing magnetic data storage, which currently requires heads to fly over a disk with spacing of about 10 nm. Maintaining such flying heights without crashing calls for exquisite design and manufacturing of disks and heads, and fundamental understanding of dynamics, non-continuum fluid mechanics, and surface forces. This has always been part of mechanical engineering and is expected to remain so even as the scales involved shrink.

One of the biggest challenges in magnetic recording is the so-called superparamagnetic limit, which occurs when the volume of a magnetic domain is sufficiently small that thermal fluctuations randomize its polarization. This can be overcome by patterning the magnetic medium. How does one manufacture highly regular magnetic bits with sizes in the range of 20 to 100 nm over a disk surface with diameter of about 3 to 10 cm? The ultimate solution to this problem will be derived from mechanical engineering.
But with all the ways in which mechanical engineering will be crucial to unlocking the potential of nanotechnology, there are challenges as well. University engineering departments must change the way mechanical engineers are educated.

Although some universities claim to have modernized their curricula, a deeper look would suggest that in most cases courses of study reflect the technological needs of the Sputnik era or perhaps an earlier time. Mechanical engineering programs need to ensure that their students are given a solid grounding in the fundamentals of physics, chemistry, and biology.

Approaches must be developed that cultivate a different way of thinking, so that students can develop intuition for phenomena occurring at the nanoscale, as well as gain an understanding for connections that bridge the nanoscale, the mesoscale, and the macroscale.

A gene gun developed at the University of Minnesota sprays a mist of DNA-bearing particles into cells. Similar devices could be used one day to spread manufactured nanoscale objects across relatively broad surfaces.

For this to happen, nanoscience and engineering concepts will need to be integrated into existing undergraduate curricula. Topics such as solid state physics, chemical thermodynamics, surface forces at the atomic and molecular scale, nanofluidics, and motion and behavior of nanoscale structures—most of which receive little if any attention in the traditional undergraduate ME curriculum—will need to be integrated into core courses such as thermodynamics, heat transfer, fluids, statics and dynamics, and manufacturing.

Textbooks need to be written or revised to incorporate this type of material with the core mechanical engineering subjects. Requiring professors of mechanical engineering to take graduate-level refresher courses on these topics is not inconceivable.

Taken together, these changes will represent a new paradigm for the education of mechanical engineers, one that, if done right, will increase disciplinary depth. At the same time, at both the undergraduate and graduate levels, students should be exposed to courses that bring in concepts from multiple disciplines, and faculty and programs must find ways to reduce the barriers to interdisciplinary dialog.

What's more, there should be a strong ethical component to this new teaching paradigm. Like any other technology, nanotechnology can have many unintended consequences that are harmful to our society and to the environment. It can also be used in counterproductive ways that could pose risks to the society.

There are many questions that we engineers must openly discuss: How could nanostructures or manufacturing of nanostructures be harmful to human health? Are there any environmental effects? Could nanotechnology reveal information that infringes on privacy? If improved health diagnostics and therapeutics facilitated by nanotechnology increase lifespan, what effect would the result have on demographics and productivity? Would this technology be accessible to the whole population, or be available to only a certain segment of our society?

It is incumbent upon us engineers to pay close attention to these societal and ethical issues related to nanotechnology. We also need to educate ourselves, the public, and the media about what is realistic and what is not, and in what time frame we could expect nanotechnology to affect our lives. It is our responsibility to do so.

Last year's workshop confirmed the emerging consensus within the mechanical engineering community that nanotechnology will have a profound impact on society and on industry, and that MEs can play a crucial role. Some major recommendations include:

• Sustained support from the National Science Foundation and other funding agencies to maintain long-term, fundamental research in nanoscale science and engineering;

• A focus on research in nanoscale science and engineering that addresses the grand challenges that affect society and humanity;

• Development of education programs that incorporate the essence of nanoscale science and engineering into undergraduate and graduate mechanical engineering curricula;

• Collaboration across disciplines by both NSF and university departments to expose graduate and undergraduate students to interdisciplinary research; and

• Research that seeks integration across scales to exploit nanoscale effects at the micro- and macroscales.

POWER PIPS

The ability to convert energy between different forms—and the capacity to use it—is the hallmark of modern civilization. Humanity will face a crisis in the coming decades due to the rate at which fossil fuels are being used and the impact this is having on the environment. Nanotechnology almost certainly has a role in resolving this crisis, and mechanical engineers are perfectly situated to capitalize on the opportunity.

It is widely recognized that renewable sources of energy such as solar electricity and biomass will gain importance in the future. However, cost is a hurdle to the effectiveness of such technologies. For example, the cost of photovoltaics must be an order of magnitude lower than its current value to make the technology competitive with fossil fuels. This could be possible if, for example, silicon-based devices, which are currently manufactured in high-temperature processes, were replaced by nanostructured plastic-based photovoltaics.

If thermoelectric devices made of materials such as silicon and germanium perform about 10 to 20 percent of the Carnot limit, they could be as competitive as cost-effective solid-state energy conversion devices. This can only occur if the semiconductors are nanostructured to control heat and charge transport. Mechanical engineers who understand these challenges better than other technologists, will almost certainly devise the solution.

The particles making up a silicon carbide film at top average only 20 nm across. A polymer material (second from top) is made of nanoscale layers. Each "carrot" made by Georgia Tech researchers (third from top) contains thousands of silica wires grown from a gallium droplet. Another group grows nanowires by depositing metals on a porous alumina membrane (bottom).

One of the biggest environmental challenges that humanity faces today is clean water. Nanostructured filters used for ion exchange hold promise for removing contaminants. Their manufacture however, must be inexpensive, and the science of nanofluidics must be understood to make these filters effective for cleaning water. Mechanical engineers can collaborate with biologists and public health researchers to resolve both these issues.

Another area of expertise for mechanical engineers, instrumentation, is also key to tapping the potential of nanotechnology. Instruments that can probe the environment with increased resolution and sensitivity lead to breakthroughs in science and engineering. The scanning probe microscopes invented in the 1980s are electromechanical devices, which require precision actuation with Angstrom resolution, microfabrication of cantilever probes, force sensing with resolution measured in piconewtons, and a fundamental understanding of dynamics and control to increase imaging speed and spatial resolution.

These stringent requirements are not limited to the microscopes, but apply to any nanoscale measurement. For example, there is a tremendous need for instrumentation in high-throughput imaging and measurement in nanomanu-facturing processes to enable automation and process control. These issues offer opportunities for mechanical engineers to provide a system-level understanding of such instruments.

Other potential applications require a mix of skills. Nanoparticles and nanowires exist on a scale similar to biomolecules such as DNA and proteins. This suggests that the biological sciences can provide crucial insights to the behavior of such material and that nanoscale devices may be used for medical applications. For instance, nanoparticles may be used as markers to study very small samples of DNA or proteins. Achieved in a high-throughput manner, this could form the basis for biomolecular analysis in extremely small volumes (on the order of single cells), which has major implications for diagnosis of disease.

In addition, the combination of nanostructures and mechanical sensors such as cantilever beams could be used in chemical or biological defense. Nanostructures such as particles and polymeric dendrimers could be designed as drug delivery systems.

Biomolecules could be used to perform non-biological tasks. Possibilities include manufacturing, energy conversion, signal amplification, and information processing. Many of these functions are already achieved in an extremely efficient manner within a cell, thanks to the genius of natural selection, but to exploit them in non-biological conditions is a nontrivial problem.

Nevertheless, applications such as manufacturing and energy conversion have always been strengths of mechanical engineers. Can we harness the power of the biomolecular machinery for mechanical applications? Research in this direction has already started.

Another field where nanotechnology may need mechanical engineers is information processing and storage. When transistors reach the scales of 20 to 30 nano-meters (a scale that will be necessary to keep up with Moore's law) quantum effects such as electron tunneling will lead to electron leakage, and this will cost power. Higher speeds will also require electromagnetic isolation, which will necessitate the use of materials that have extremely low thermal conductivities. In addition, novel cooling technologies that directly interface with electronic and optoelectronic chips must be developed.

To create chip designs that solve these thermal problems, technologists will need a basic understanding of how heat flows in nanostructures and across interfaces. Mechanical engineers have just this sort of expertise.

Nanotechnology and Daily Life

In general we are not aware of issues that confront us about science, technology and others super complicated specialized fields. The finished product is normally the result of perhaps many years of study, field-laboratory observation and research. Gadgets we religiously use such as digital music players, cameras, mobile phones have not just materialized.

In the case of the Nanotechnology there is a small but powerful empire of scientist focused on the study of a world microscopically dimensioned. Nanotechnology is a multi-disciplinary field of technology and applied science that is solving problems through the knowledge and application of one or more natural scientific fields.

The scale which embraces the Nanotechnology field is the realm of nanostructures and atoms. There are currently some discussions between scientists and experts about the real measurable range or scale of the Nanotechnology. Of what we are completely sure is we can not see it with our human eye but when we talk about nanostructures we commonly refer to a range between is 1 to 100 nanometers.

How can we really appreciate and understand that? Surely we need be more aware about the units of measures involved. For example: a centimeter corresponds to 100 of a meter, a millimeter corresponds to 1000 of a meter and a micrometer corresponds to 1 million of a meter. All of these measures are visibly-huge-enormous compared to the 'nano-scale'. According to the reputable Berkley Lab, a nanometer (nm) is one-billion of a meter. Of course that is completely invisible, smaller than the wavelength of the visible light a 100.000 the width of the human hair.

If we compare the nano-scale (that is the scale used for the nanostructures) and the atomic scales, we have that an atom has a diameter near to 0.1 nm and the nucleus of an atom is evidently so much smaller about 0.00001 nm. All matter in the universe and all is around us is made up of atoms. All inside and outside us is matter and our human bodies are formed from millions of living cells. Though the living cells work like natural nano-machines and in the atomic scale the elements are in a very basic level but in the nano-scale we can join these atoms and make almost everything.

With all this information now we are more conscious about the subject. For some scientist, the Nano-science is a very new science but for others it is just an extension of sciences that currently exists into the nano-scale or just a newer-modern-used-term.

How can Nanotechnology help us in our daily life? For the commoner, the fields of science seem sometimes so theoretical, but there are many applications today that are linked to Nanotechnology. Scientist using nanostructures can reproduce things like gem stones, food and much more by self-replication nano-robots.

A very important field for this new science is health. Nanorobots or Nanomachines which are devices ranging in size from 0.1 to 10 micrometers can be used in medical technology to detect, analyze and identify through nano-sensors cancer cells to then destroy them. They can also help to identify an early diagnosis for cancer. Nanotechnology in the environment can be used to detect and measure the concentration of toxic elements more efficiently.

There are a wide range of applications and uses for Nanotechnology. In the case of food it is used to develop packaging more safely through a nanocomposite which can increase or decrease gas permeability, heat resistance. In the household for example, nanotechnology applications are already responsible for developing devices for self-cleaning windows, dishes, ceramics etc.

Many people experience eye irritation caused by the ultraviolet rays. Thanks to Nanotechnology, advances have been made to produce the first anti-reflective ultrathin polymer sunglasses. In optical surgery, nano-optics increase the precision of pupil repair and other type of surgery using laser technology.

Unquestionably we are now receiving the benefits of the Nanotechnology in many ways. We can improve our knowledge of nanotechnology according to our self interest. In our daily life there are many things we cannot see and touch which are incredibly powerful and extremely significant for the modern world we live today. Nanotechnology is clearly going to play a major role in the future development of many disciplines

Nanotechnology is an umbrella term that covers many areas of research dealing with objects that are measured in nanometers. A nanometer (nm) is a billionth of a meter, or a millionth of a millimeter.

In the early 20th century, Henry Ford built a car manufacturing plant on a 2,000-acre tract of land along the Rouge River in Michigan. Built to mass-produce automobiles more efficiently, the Rouge housed the equipment for developing each phase of a car, including blast furnaces, a steel mill and a glass plant. More than 90 miles of railroad track and conveyor belts kept Ford's car assembly line running. The Rouge model was lauded as the most efficient method of production at a time when bigger meant better.

The size of Ford's assembly plant would look strange to those born and raised in the 21st century. In the next 50 years, machines will get increasingly smaller--so small that thousands of these tiny machines would fit into the period at the end of this sentence. Within a few decades, we will use these nanomachines to manufacture consumer goods at the molecular level, piecing together one atom or molecule at a time to make baseballs, telephones and cars. This is the goal of nanotechnology. And as televisions, airplanes and computers revolutionized the world in the last century, scientists claim that nanotechnology will have an even more profound effect on the next century.

Building with Atoms

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. Humans still have a lot to learn about the idea of constructing materials on such a small scale. Consumer goods that we buy are made by pushing piles of atoms together in a bulky, imprecise manner. Imagine if we could manipulate each individual atom of an object. That's the basic idea of nanotechnology, and many scientists believe that we are only a few decades away from achieving it.

Nanotechnology is a hybrid science combining engineering and chemistry. 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 nanotechnology is to manipulate atoms individually and place them in a pattern to produce a desired structure. There are three steps to achieving nanotechnology -produced goods:

• Scientists must be able to manipulate individual atoms. This means that they will have to develop a technique to grab single atoms and move them to desired positions. In 1990, IBM researchers showed that it is possible to manipulate single atoms. They positioned 35 xenon atoms on the surface of a nickel crystal, using an atomic force microscopy instrument. These positioned atoms spelled out the letters "IBM." You can view this nano-logo.
• The next step will be to develop nanoscopic machines, called assemblers , that can be programmed to manipulate atoms and molecules at will. It would take thousands of years for a single assembler to produce any kind of material one atom at a time. So, trillions of assemblers will be needed to develop products in a viable time frame.
• In order to create enough assemblers to build consumer goods, some nanomachines, called replicators, will be programmed to build more assemblers . Trillions of assemblers and replicators will fill an area smaller than a cubic millimeter, and still will be too small for us to see with the naked eye. Assemblers and replicators will work together like hands to automatically construct products, and will eventually replace all traditional labor methods. This will vastly decrease manufacturing costs, thereby making consumer goods plentiful, cheaper and stronger. In the next section you'll find out how nanotechnology will impact every facet of society, from medicine to computers .