SEMINAR REPORT ON NANOTECHNOLOGY

BY ANAND.M.PATIL

MECHATRONICS AND NANOTECHNOLOGY: MANUFACTURING ENGINEERING CHALLENGES

CONTENTS1. INTRODUCTION TO MECHATRONICS 2. MECHATRONICS 3. EXAMPLES 4. INTRODUCTION TO NANOTECHNOLOGY 5. HISTORY 6. EXAMPLES 7. MANUFACTURING CHALLENGES 8. APPLICATIONS

1.

I-Robots

STAR TREK

As engineers it makes us think do they have any truth? Is there any way in which we can make this Science Fiction a science reality? Is there any means that can help us achieve our dream?

Mechatronics is the synergistic combination of mechanical engineering, electronics, controls engineering, and computers ... Mechatronics is adding intelligence to a mechanical design. As technology advances, designs that were once purely mechanical are now best done with electronics or a combination of both. Perhaps the best way to understand mechatronics is to look at example applications where microcontrollers have enhanced or replaced the mechanical and analog components of a design.

1 Introduction:Mechatronics is attracting more and more attention. The term is used for a wide variety of applications. Sometimes it is even used for applications that, judged by a more narrow definition, hardly can be seen as a mechatronic system. The Industrial Research and Development Advisory Committee of the European Union, (IRDAC, 1986) has formulated a general accepted definition of mechatronics: The term mechatronics refers to a synergistic combination of precision engineering, electronic control and systems thinking in the design of products and manufacturing processes. It is an interdisciplinary subject that both draws on the constituent disciplines and includes subjects not normally associated with one of the above. Essential in this definition is the systems approach . This implies that the system is designed and optimised as a whole and not in sequential steps. However, not every design made by means of a systems approach is a mechatronic design. By concentrating on a limited application area, a mechatronic designer should have the domain-specific knowledge that enables him to realise really advanced products. Mechatronic design also implies teamwork. Specialists with a background in mechanical and electrical engineering, control and computer engineering should co-operate in a team, in all phases of the design, to come to a synergistic combination.

Electronic Fuel Injection Electronic Fuel Injection (EFI) works on two major principles. The first is the ability to measure the mass of the air flowing through the intake manifold. The second is the ability to measure the exhaust gas oxygen content. Using sensors for the observation of these variables, a properly programmed EFI system can inject a nearly stoichiometric mix of fuel and air into the motor's cylinder and thus obtain the best combustion and fuel economy characteristics. The system is timed by a cam position sensor and is fine tuned with data from a variety of other sensors including exhaust gas temperature, throttle position, and valve position. Fuel line pressure, motor RPM, fuel jet flow rate, and intake gas pressure with A/F ratio, exhaust gas temperature, throttle position, and mass-air flow. There are many benefits to a mechatronics solution. These benefits include: Enhanced features and functionality Incorporating a PIC microcontroller More user-friendly Power windows, power door locks, keyless entry Precision control Flow rate, speed, position

More efficient Pulse Width Modulation (PWM) Lower cost Microcontroller-based approach Flexible design (reprogrammable) Software controlled parameters More reliable Optical encoder and digital display Smaller

Safer

Figure 1 Mechatronics is a synergistic combination of mechanical and electrical engineering and information technology Finally a good design philosophy is essential. Buur (1990) gives a more concise definition: Mechatronics is a technology which combines mechanics with electronics and information technology to form both functional interaction and spatial integration in components, modules, products and systems . The aspect of spatial integration, in addition to functional integration, points to an interesting feature found in many mechatronic designs. Although the word mechatronics is new, mechatronic products have been available for some time. In fact all electronically controlled mechanical systems are based on the idea of improving the product by adding features realised in another domain. Good mechatronic designs are based on a real systems approach. What has been lacking in the past, and is often still lacking today, is that systems are not designed as a whole. Mostly, control engineers are confronted with a design in which major parameters are already fixed, often based on static or economic considerations. This prohibits optimisation of the system as a whole, even when optimal control is applied. When tacho feedback is applied to an electrical motor, the mechanical time constant of the motor can be reduced at the expense of a better electric power amplifier. Old gramophones where equipped with heavy turntables in order to guarantee a constant number of revolutions. In the last days of vinyl disc players, more sophisticated designs used tacho feedback in combination with a light turntable to achieve the same. But a really new design was the compact disc player. Instead of keeping the number of revolutions of the disc constant, it aims for a constant speed of the head along the tracks of the disc. This means that the disc rotates slower when tracks with a greater diameter are read. The bits read from the CD are buffered

electronically in abuffer that sends its information to the DA-converter, controlled by a quartz crystal. Thisenables the realisation of a very constant bit rate and eliminates all audible speed fluctuations.Such a performance could never be obtained from a pure mechanical device only, even if itwere equipped with a good speed control system. In fact the control loop for the disc speeddoes not need to have very strict specifications. It should only prevent overflow or underflowof the buffer. The high accuracy is obtained in an open loop mode, steered by a quartz crystal

Figure 2. Combination of closed-loop and open-loop control in a CD-player The flexibility introduced by the combination of precision mechanics and electronic control has allowed the development of CD-ROM players, running at speeds more than 30 times faster than the original audio CD s. A new way of thinking was necessary to come to such a new solution. On the other hand, the CD player is still a sophisticated piece of precision mechanics. No electronic memory device can compete yet economically with the opto-mechanical storage capabilities of the CD and its successor the DVD. But this may change rapidly. Nowadays, electronic buffers with a memory capacity of up to 10 seconds, allow the use of these devices during outdoor exercises, such as jogging. The first devices that deliver CD-quality sound and use only solid state electronics in combination with powerful data compression techniques have become available already. In the packing industry, many devices still rely on, for instance, gravity to get a certain behaviour of the product and the packing material. Such systems are sensitive to disturbances. In addition, a new packing requires a redesign or at least readjustment of the machine. By implementing active motion control, a more reliable, faster and more flexible device can be constructed. If an aeroplane should have stable flight properties under pure manual control, the design

possibilities are limited. When under all circumstances the presence of an automatic controller as a support system for the pilot is accepted, implying that it should be as reliable as the rest of the construction, aerodynamically more efficient designs become feasible. Other good examples of mechatronic systems can be found in automotive applications such as ABS, electronic stabilisation systems and active suspension systems as well as automated highways. In the Mini Symposium Mechatronics in Control System Design at the Control '98 Conference in Swansea various applications and design issues were presented. Among these were papers on A knowledge-based mechatronics approach to controller design (Bradshawand Counsell, 1998). Papers on applications involved Vision-in-the-loop control applications in textile manufacture (King, 1998), Development of a fuzzy behavioural controller for an autonomous vehicle (Tubb and Roberts, 1998) and Development of adaptive cruise control systems for motor vehicles (Richardson, Clarke and Barber, 1998). The synergy of different disciplines allows the design of really advanced and simultaneously affordable products and production machines. 2 Mechatronic Design Mechatronics is more a way of thinking than a completely new discipline. It still needs advanced knowledge of specialists from different disciplines who meet each other in a mechatronic design team. Mechatronics is a design philosophy. It has been mentioned in the introduction that it is important to make a design from a systems approach in order to get the best possible performance. But it is not realistic, nor needed to invent the wheel again and again, because time to market is an important issue. Mechatronic designs of production machines can help to react faster to market demands. A flexible production line that can be reconfigured by means of software is much easier to adapt than conventional lines that require that mechanical devices be manually reconfigured. But also in the design stage of products and production means, time to market is an important issue. By developing proper tools and knowledge bases, existing knowledge can be made available to less experienced designers. Such knowledge bases should not only be filled with standard solutions for mechanical components, but also with proper CAD tools and mathematical models of these components and with control structures suited for certain classes of problems. The knowledge base could also contain standard software modules that have been tested well; thus enabling the automatic generation of code for a computer based controller. One may doubt whether the design process could ever be done automatically. Although the power of computational intelligence is increasing rapidly, the human creativity can not yet be beaten by a computer. But providing the human designer with proper tools can considerably increase his productivity. 2.1 Tools for modelling, simulation and controller design Simulation can play an important role in the process of designing mechatronic systems. With computer simulation alternative designs can be compared and evaluated without

the cost involved with building real prototypes. Simulation tools used in control engineering are mostly based on a block diagram representation of the underlying mathematical model. These models have a direct connection with the transfer functions of the various components of the system. If necessary, they can be extended with nonlinearities. For the design of mechatronic systems transfer functions and block diagrams are often not the most appropriate models. A basic assumption in a block diagram is that the different blocks do not influence each other s properties, or that any interaction between the blocks has been accounted for in the parameters. This implies that they cannot easily be replaced by other system components. Another problem is that the parameters of various physical components appear in various combinations and at various locations in the block diagram. Unless there is a supporting system available that automatically relates the different parameters of the mechanical system to the parameters of the block diagram, investigating the effects of parameter changes becomes a tedious job. Iconic diagrams like basic electrical network diagrams or mechanical diagrams do not have this problem. Energy based modelling approaches, e.g. the bond-graph approach, can form a link between iconic diagrams and mathematical equations. Such models can help to increase the insight in the design and may suggest alternative solutions (Figure 3).

Figure 3. Iconic diagram and bondgraph of a mobile robot In the Control Laboratory at the University of Twente a software package (20-sim) has been developed that supports the modelling and simulation with bond graphs, in addition to the use of equations and block diagrams. Versions 3 of this program also supports iconic diagrams and object orientation. The latter enables to start with a

simple design, using only basic functions of the various components. When the design process proceeds, more complex representations of the component can be incorporated in the model, and their effect on the system behaviour can be examined. A model of a component is thus not fixed. It can have various shapes. The models are polymorphic i.e. they can have various levels of detail. Also viewing the system in various representations or in multiple views can help to get a good insight in the properties of the system (Figure 4). Among these various representations are: representations in the frequency domain, time domain, differential equations, bond graphs, iconic diagrams and block diagrams as well as more fancy representations like stereo views as found in virtual reality. 20-sim 3.0 can automatically generate (linear) state space descriptions from the simulation code. This allows the use of tools like Matlab for further analysis, control system design and generating other representations. Demo versions of 20- sim are available from the web.

Figure 4. Multiple views of a servo system in open loop and closed loop These concepts and their impact on mechatronic design have been described in the PhD thesis of De Vries (1994) and have been further worked out into a concept for a modelling and simulation language by Breunese (1996). Related work is done e.g. in the Schemebuilder project (Bradley, Bracewell and Chaplin, 1993). Proper software tools should support various representations and should allow converting one representation into another one. In order to advance the applications of real mechatronic designs it is essential that design knowledge is formalised and brought together in a knowledge base. This will enable reuse of this knowledge. This knowledge base should contain reusable models, standard design approaches and support tools to retrieve the knowledge and to make a new design out of it. A control engineering challenge is to introduce modern control methods into standard mechatronic designs. In many cases, simple PID-type controllers are applied because of their ability to perform reasonably well without too many tuning and design efforts. It is a challenge to develop tools that allow the application of more advanced controller algorithms with the same or even less effort as required for tuning a PID-controller. By developing tools that support such a design for various classes of systems, this should be possible. 3 Examples A few examples of mechatronic designs of projects that were recently carried out in the Control Laboratory of the Faculty of Electrical Engineering of the University of Twente will be shortly discussed here. All these projects were performed in the multidisciplinary environment of the Cornelis J. Drebbel Institute for Systems Engineering (formerly MRCT), a cooperation of the faculties of Electrical Engineering, Mechanical Engineering, Applied Mathematics and Computer Engineering. The projects indicate that good mechatronic designs require attention for the mechanical design, the choice of the sensors and of the control system and for the computer implementation.

3.1 Alasca project In the Alasca project a device for placing IC s at a printed circuit board has been developed. It should replace older difficult to control pneumatic equipment by an electric servo system that should be able to rotate and translate simultaneously, with a high speed and accuracy. Adesign team of a mechanical and electrical engineer was formed to design the motor and its control (both students from the Mechatronic Designer postgraduate course). An induction type of motor was developed with two sets of windings, one to realise the rotation and another one to realise the translation (Figure 5).

Figure 5. The windings for the Translational motor (TLIM coils) and for the Rotational Motor (TRIM coils) To achieve the required accuracy, air bearings were used. This could only be done if contactless sensors were available to measure the two motions. The inductive sensor for measuring the translation was more or less a standard solution, although care had to be taken to use it in the presence of the magnetic fields of the motor. A contactless rotational sensor that should be able to accurately measure the rotation even when the actuator performs translational motions had to be developed. The sensor consists of a combination of three LED s at the stator, a sheet of polarising material at the rotor/ translator and three photo diodes, covered with sheets of polarising material under angles of 120 degrees at the stator

(Figure 6). The sensor signal is compatible with the signal of a synchro. A standard synchrotodigital converter could thus be used as an interface between the sensor and the computer, yielding a resolution of 14 bits.

Figure 6. The rotational sensor Because induction motors have a low efficiency, especially in low-power servo applications, especially attention was given to minimising the losses. This resulted in the minimum dissipation control algorithm. By using proper computer support tools, the design could easily be adapted to changing requirements with respect to the dimensions of the actuator during the development process. Parallel to the motor design, a system was developed that could replace soldering of the leads of the IC, by laser welding. Besides attention for the process conditions of the laser welding, such as the required power, and the angle of attack of the laser beam, a fast and accurate servo system was developed, that finally enabled welding of 80 leads per second. More details of this project can be found in the paper of Van Amerongen and Koster (1997). 3.2 Learning Feed Forward Control Another project carried out by a student of the Mechatronic Designer Course was the development of a learning feedforward controller for an industrial linear permanent magnet motor used to build Cartesian robots. In a linear motor system, a linear relative

movement exists between the translator and the stator. So the coils are moving along with the translator while the magnets are static. Due to the protrusions or poles on the translator, a force (in moving or opposite direction) is acting on the translator whenever the poles of the magnets and the poles on the translator are not aligned. So the translator has a number of preferred positions, independent of the fact whether a current is applied to the coils or not. The force experienced by the translator is approximately sinusoidal as a function of the position. The force described here is formally called reluctance force. In most brushless permanentmagnet motors this force (torque in a rotating motor) is undesirable and is referred to as cogging force or detent force. Feedback control can only partly compensate for the disturbance forces caused by cogging. Feedforward control is only partly effective, because the force is only approximately sinusoidal, because the magnets and the distances between them are not exactly similar. The industrial motor and its controller could not achieve accuracy better than 100 m, while 10 m was desired. In order to achieve a better accuracy, more tight specifications of the magnets and their relative positions are a possible but expensive solution. The alternative is compensation tuned for each single motor. By applying a learning feedforward, realised with a neural network, accuracy better than 5 m could be achieved (limited by the sensor accuracy). Learning takes approximately ten trial motions and is especially effective for repetitive motions, but because the inputs of the network are the desired position and velocity, rather than time, it performs well with non-repetitive motions too. In addition, the network will update itself when needed. The neural network uses the feedback signal as a training signal, based on the idea that with a proper feedforward the feedback signal should be zero, except for signals due to random disturbances (Figure 7). By selecting a proper learning speed, the latter will not be learned. Typical results are shown in Figure 8. This approach has also been applied to the path controller of the mobile robot described in the next section (Starrenburg, J.G., et.al., 1996) as well as to the control of a flexible beam (Velthuis, De Vries and Van Amerongen, 1996).

Figure 7. Learning feedforward control. The neural network is trained by the output of he feedback controller

Figure 8. Error signal before training the network (about s100m) and after ten standard motion patterns (about s5m) 3.3 MART, a factory of the future The Mobile Autonomous Robot Twente (MART) project aimed in the first place at investigating how different disciplines can cooperate in a mechatronic team. The objective of such a team should be the development of a technical system with solutions contributed from different disciplines. An automated assembly factory was adopted as a subject. It was a common effort of participants from mechanical engineering, control engineering and computer science. It resulted in an autonomously

moving vehicle that, while riding a predestinated, product dependent route along a number of stocks, collects components and assembles them by a manipulator on board the vehicle. A vehicle, a manipulator, a gripper exchange system, a docking system, a navigation system together with all the hard and software for task and path planning were developed, built together and tested. On board the vehicle, there is a 4-d.o.f. assembly robot (Figure 9).

Figure 9. MART robot The robot takes components from a part supply system to the vehicle s deck and performs the assembly operations, even during riding. The design process started with the evaluation of basic concepts based on simple models. The outcomes of these evaluations directed the design of the different parts of the system. The more the designs grew, the more detailed the modeling became. It was interesting to see that deviations between the early predictions, the simulations in the final stage and the practical results, remained within 20%. Consequently, simple modeling was of much use in order to direct the project (Oelen, 1995 The upper frame contains the majority of the mass, especially the batteries. The optimal distribution of the weights was determined with simulations. more mass is attributed to the upper frame the more it acts as a low pass filter. The upper frame will be the interface between the manipulator and the docking mechanism. The docking mechanism will ask for three points, rigidly connected to the manipulator base. Therefore, a tetrahedron-like upper frame was adopted . On the tip plane, the manipulator is carried. The lower frame is supported by a swivel wheel at the front and two servomotor driven wheels at the rear. These drives contain encoders as a provision for odometry. Many more design aspects were involved (Van Amerongen and Koster (1997) and Koster (1997)). The earlier-mentioned learning feedforward controller was also used for the path following systems of the MART (Starrenburg, J.G., et.al., 1996). Starting with a rather elementary feedback controller, based on a simple model of the robot, the error over a typical path was as large as 12 cm. After 3 trials the error was already considerably smaller and after 15 trials the error was within the specifications (Figure 12). The learning feedforward controller even outperformed a feedback controller based on an extensive model of the robot (Figure 13)

Figure 12. Learnig behaviour of the learning feedforward controller of the MART

Figure 13. Comparison of a learning feedforward controller and a model based controller 3.5 Smart disc A recently started project deals with the design of a device that combines a sensor, controller hardware and an actuator in one single small disc that can be placed in highprecision mechanical constructions to reduce deformation due to high-frequency vibrations. In the smart disc piezo material is used as sensor (to measure the deformation) as well as actuator (to reduce these deformations). All hardware necessary to compute the proper control actions will be integrated on the device itself (Figure 14). Preliminary experiments have indicated that small, but high frequency, vibrations in the construction can effectively be reduced. This is an another example of a device with functional and spatial integration. More information is available on the web-site of the control laboratory http://www.rt.el.utwente.nl/mechatronics).

Figure 14. Smart Disc 4 Conclusions In this paper it has been stated that mechatronics is a design philosophy for the design of electro-mechanical systems, based on a systems approach. A successful introduction in industry requires that proper support tools be available. Some of these tools have been discussed: modelling and simulation tools, based on reusable models. The concept of polymorphic modelling that enables a design model to become gradually more complex and realistic, was discussed shortly. It was also concluded that tools for easy design of complex controllers for mechatronic systems are needed. A few examples demonstrated some aspects of mechatronic design.

NANOTECHNOLOGY

ABSTRACTThe term nano-technology has evolved over the years via terminology drift to mean anything smaller than micro technology such as nano powders, microprocessors, micro-data chips, micro machines, which have a capacity much much more than its macro ones .. Nanotechnology gets its name from from the measurement called nanometer, which is one-billionth of a meter 1/80000 the size of human hair. A nanometer comprises of many small atoms manipulating to form molecule ,the building blocks that produce new materials with exact properties they desire:smaller, stronger, tougher, lighter and more resilient than what has come before Also you will find Microelectronic devices First, in the 1950s and 1960s, solids state devices-transistors-replaced vacuum tubes and miniaturised all the devices(e.g., radios, televisions and computers) that originally had been invented and manufactured using tube technology. Then, starting in the mid-I960s, successive generations of smaller transistors began replacing larger ones. This permitted more transistors and more computing power to be packed in the same small space If computers are to continue to get smaller and more powerful at the same rate, nanotechnology will need to be employed for miniature electronic devices One of such technologies to get the most-micro transistor is scaling of transistors

INTRODUCTIONJust imagine hard drive capable of holding 1000 times as much data than those used in computers today. No, this is not something straight out of any science fiction. It is the future of electronics and computing supported by nanotechnology. The advances in nanosciences may one day shrink modern day desktop PCs to the size of wrist watches. It's not just the size that is going to matter, the nano-revolution is going to give a big boost to power sources, chip technology and semi-conductors. Nanoscience is the science that deals with substances in which one dimension is less than 100 nanometre (nm). A nanometre is one billionth of a metre and the diameter of human hair is of 50,000 nm. Nanotechnology is the technology of designing, fabricating and applying nanosystems. A nanosysytem is a system that is synthesised to a nanometre scale (a nanometre is a billionth of a metre and spans approximately 10 atomic metres).

HOW WILL NANOTECHNOLOGY CHANGE OUR LIVESOne of the first obvious benefits is improved manufacturing. We are modifying familiar manufacturing systems to offer precision on the atomic scale. This will give us greater understanding of the building of things, and greater flexibility in the types and quantity of things we may build. We will be able to expand control of systems from the macro level to the micro level and beyond, while simultaneously reducing the cost associated with manufacturing of products. Nanotechnology will touch our lives right down to the water we drink and the air we breathe. Once we have the ability to capture, position and change the con figuration of a molecule, we would be able to create filtration systems that will scrub the toxins from the air or remove hazardous organisms from the water we drink.

AMAZING SPECIAL FEATURES !!!The typical specialised nano-factory will be a breadbox to the refrigerator-size object, with trillions of parallel assembly lines converging in a tree-like structure to produce ever-larger sub-components of the end product. For something as small as a foglet, the factory could be quite a bit smaller, of course. But how would one breathe when the air is a solid mass of machines? Foglets occupy only a small percentage of the actual volume of the air and need lots of space to move around easily. Thus there's plenty of air left to breathe. Fog could enter your lungs (and scrub them of air pollution, smoke, and what not with every breath), simulating the activity of unoccupied air or forming a fog-free region around you into which fresh air was continually fanned

NANOTECHNOLOGY AN OVER VIEW Abstract:Nanotechnology is often termed as a system innovation, implying that it is expected to initiate an increase in number of innovative developments in various sectors of technology,various social areas of applications and economic sectors.

Introduction:One of the biggest scientific trends of the 21st century has been centered on something incredibly small: nanotechnology. But what is nanotechnology? That is the most difficult question to answer, even though it s all over the news these days. The crux of the problem is that it is beyond the understanding of most people. Unless we have studied it extensively in university (and even then the picture isn t necessarily complete) we won t know what a quantum dot is. We will need to know the underlying science that drives it, the tools we use to apply it, and the potential benefits and dangers of it. Nanotechnology is a broad term for the application of scientific understanding towards fabricating devices and materials at the nanometer scale. Nanotechnology takes its name from a unit called nanometer-NM, which means it s the one billionth of a meter. [1nm = nanometer (1,000,000,000 nm per m, or 10-9 m)]. Nanotechnology is primarily characterized by its overall dimension: the Nano -world. The Nano-world exists at the level of single molecules and atoms-the size of a millionth of a millimeter. Nanotechnology involves building sophisticated products from the molecular scale. As the molecule is the smallest particle of matter that exists independently, it cannot be ruled by any of us, but the technologists have started ruling the same understanding the molecular world as a tough process. This kind of molecular manufacturing will in fact result in high quality, smart and intelligent products that are 100% efficient, produced at low cost with little environmental impact. Nanotechnology is expected to have an enormous potential for innovation because it may create effects which have not yet been feasible with any other technologies. The far reaching possibilities of nanotechnology development, which are currently being assessed according to feasibility, find their echo in partly extreme judgments of the technology. The specific characteristics of this dimension are that nano -particles show a completely different behavior to their larger, coarser pendants. The relatively big specific surface of nano particles usually leads to an increase in their chemical reactivity and catalytic activity. The relatively

small amount of atoms within nano-particles offsets the quasi-continuous solid state of the particle, leading to new, deviating, optical, electrical and magnetic features. From these basic features and characteristics of nano-technology, a number of possible positive and problematic (negative) effects can be derived.

Characterization of Nanotechnology:To know about the impact of a technology, we require a familiarity with three basic elements. Viz., 1. An Agent (the technology, substance etc whose possible effects are to assessed); 2. An impact model (a scientifically verifiable theory on how the agent acts on a potential target) 3. A target entity upon which the agent acts. One of the basic principles of nanotechnology is positional control. At the molecular scale, the idea of holding and positioning molecules is new. Before discussing the advantages of positional control at the molecular scale, it is helpful to look at the property of self-assembly of molecules. A basic principle in self-assembly is selective stickiness i.e., if two molecular parts have complementary shapes and charge patterns-(one part has a hollow where the other part has a bump, and one part has a positive charge where the other part has the negative charge). Then they will tend to stick together in one particular way. This bigger part can combine in the same way with other parts, letting us build a complex whole from molecular pieces. 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. For ex: we don t know how to self assemble shatterproof diamond without using positional control through nanotechnology. 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 will 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 in discriminatory sticky parts (radicals, carbines and the like). These parts cannot be allowed to randomly bump into each other (or much of anything else, for that matter) because the would stick y together when we didn t want them to stick together and form messy blobs instead of precise molecular machines. We can avoid this problem if we can hold and position the parts. Even though the molecular parts that are used to make diamond are both in-discriminatory and very sticky (more technically, the barriers to bond formation are low and the resulting covalent bonds are quite strong), if we can position them, we can prevent them from bumping into each other in the wrong way. When two

sticky parts do come into contact with each other, they will do so in the right orientation because we are holding them in right orientation. In short, positional control at the molecular scale should let us make things which would be difficult or impossible to make without it. Given our macroscopic intuition, this should not be surprising. If we could not use our hands to hold and position parts, we must develop the molecular equivalent of arms and hands .

Life Cycle Assessment (LCA) for evaluation of nanotechnology application:Following on from the characterization of nanotechnology and the hitherto existing production methods, we have to next identify the sustainability effects by process monitoring and evaluation of specific examples of nanotechnology applications. The most advanced and standardized procedure for evaluating environmental aspects associated with a product and predicting the product specific environmental impact is the method of life cycle analysis (LCA) which should consist of the following stages: 1. Establishing the objectives and the scope of the assessment. 2. Life cycle inventory. 3. Appraisal of impact. 4. Overall evaluation. Following is the flowchart which clearly illustrates interdependence of these stages.

Establishing the objectives and the scope of the assessment

Direct applications: -Development and improvement of products. -Strategic Planning.

Life-Cycle Inventory -Political decision-making process. Appraisal of impact Overall evaluation

The arrows between the individual stages highlight the interactive nature of the procedure with the outcome of a given step always being fed back into the precedin stage and resulting, if g

necessary, in the repetition of the procedure. The LCA approach also includes methodological deficits: for some of the impact categories there exists no commonly accepted impact model.

Manufacturing Challenges For 2020

y A new space transportation system being developed could make travel to Geostationary Earth Orbit (GEO). A space elevator made of carbon Nano -tubes. y Composite ribbon anchored to an offshore sea platform would stretch to a small counterweight approximately 62,000 miles into space. y Mechanical lifters would climb the ribbon, carrying cargo and humans into space, at a price of only about $100 to $400 per pound. y This will require us advancement in Mechatronics to control the various aspects of these elevators like balancing as it moves up and down. y Nano-robots are required to take care of the Maintenance of these elevators

without putting the human life in jeopardy.

Assemblers and Replicators

y Construct complex product automatically. y Replace traditional labors. y Eventually replicate diamonds, water and food. y But it is possible only with the help of Mechatronics.

Automobiles

y The Automobiles of the future may not run on roads or might not even require a driver. y With the help of Mechatronical systems we might just need to say the destination and we would be flown to it. y The vehicles of future might even be perpetual machines which might use various methods like electron tunneling or other methods coupled with Super computers to drive them.

Artificial Intelligence

y The Research and development in these fields could result in Super Computers being very affordable and smaller. y This could even result in Humanoids that are very intelligent and act ive as shown in the movie Artificial intelligence. y This could also result in creation of artificial organs that could replace ours to give

humans a very long life.

Road Blocks

1. 2. 3. 4.

Quantum mechanics Electron tunneling Conductivity of material Melting point

y Overwhelming amount of data

1. Nano-Materials could be toxic 2. Being very small they can pass the blood brain barrier. 3. Many Nonmaterial's could cause ailments like Lung fibroses.

Broad Application of Nanotechnology:Wide areas of application of nanotechnology are found in every field and some of them are mentioned as under: Industry & Production of goods Stain resistant and wrinkle free fabrics Amusement and toys Nano-physics Nano-chemistry Nano-energy and, Nano-medicine and many more..We will look into the aspects of application in nanotechnology in industry & production of goods for the present:-

Application in Industry & Production of Goods:Molecular manufacturing is the basis of nanotechnology which will lead to production of smart, reliable and intelligent products. With nanotechnology, industrialists plan to bring thorough control of the structure of matter, and hence will be able to build objects atom by atom specifications. Nanotechnology will hence make possibly a huge range of new products. The products that are available in the market today are not 100% efficient and are worn off when handed roughly. But with the introduction of

nanotechnology, we can have better and reliable products because better quality can be achieved by molecular manufacturing. By building things with atom by atom control, flaws can be made rare and non -existent. Nanotechnology will also result in inexpensive

production or production cost will be considerably reduced. Following are few examples of application of nanotechnology in production of goods:

1. Application in Automotive & Transportation Industry:Micro and Nanotechnologies have already made an impact in the automotive and transportation industry. In Automobiles, 1. Micro chips reg ulate engines; 2. New technologies control car and truck braking, and 3. Electronic tuning ensures cleaner engine burn. The automobile is one platform that is beginning to take advantage of nano composites in diverse components and systems ranging from catalytic converters that more efficiently convert combustion by -products to benign emissions, to economical light weight plastics and coatings that enhance fuel efficiency and vehicle durability.

Establishing the objectives and the scope

Direct applications: -Development and improvement of products. -Strategic Planning.

Life-Cycle Inventory Appraisal of impact

2.

Application in Food-Sector:Nanotechnology also has applications in the food sector. Many vitamins and their precursors, such as carotinoids, are insoluble in water. However, when skillfully produced and formulated as nano-particles, these substances can easily be mixed with cold water, and their bioavailability in the human body also increases. Many lemonades and fruit juices contain these specially formulated additives, which often also provide an attractive color.

3. Application in Cosmetic Sector:In the cosmetics sector, BASF has for several years been among the leading suppliers of UV absorbers based on nano-particulate zinc oxide. Incorporated in sun creams, the small particles filter the high-energy radiation out of sunlight. Because of their tiny size, they remain invisible to the naked eye and so the cream is transparent on the skin.

A Future based on Reflection and Responsibility:As nanotechnology continues to develop, it is likely that the debate over regulation will develop as well. Experience with recombinant DNA indicates that early concerns about safety are likely to be overblown, and that an effective regulatory regime can be based on a combination of consensus and self-regulation. Though there are likely to be some calls for a complete ban on nanotechnology, such a ban is certain to fail, and it s unworkability means that such calls will probably come mostly from anti-technology groups that command little political support. Similarly, efforts to limit nanotechnology to military applications are likely to face technical and political hurdles as knowledge diffuses and the public seeks access to potentially life-saving technologies. More responsible calls for regulation as well can be met through an approach that will not stifle the development of nanotechnology. Sound knowledge, calm reflection, and an aversion to media hysteria will be key requirements of those dealing with a new and highly technical subject with endless implications.

CASE STUDY: 1. Non-volatile memory from nano-particles:Researchers from University of California at Los Angeles and ROHM and Haas Electronic material company have devised a potentially low cost, high speed nonvolatile memory from polystyrene and gold nano-particles. This retains information when it is not powered. The memory can be easily manufactured from an inexpensive material making it potentially much cheaper than today s flash memory chips. It can be read to and written electronically, making it potentially much faster than today s CD and DVD s. According to researchers, layers of the film can be stacked making it possible to store even more information in a given area.

2. Boeing Developing Nanotechnologies for New Aircraft :The Chicago Sun Times has reported that Boeing s Phantom Works, is developing new materials using nanotechnology. The Company is also developing new materials for use in building lighter but stronger aircraft, specialized coatings-that means, planes do not need to be repainted. They are also planning to develop lighter, smaller, more powerful and longer -lasting batteries for satellites.

Ethical Issues:y Unemployment

Conclusion:Therefore, nanotechnology surely promises a brighter future and it will also help produce environment friendly products. Nanotechnology will mean greater control of matter making it easy to avoid pollution. Sophisticated products could even be made from biodegradable materials. Hence, nanotechnology will make it easy to attack the causes of pollution at technical level.

Bibliography: www.nanotechnologybasics.com www.scrbid.com www.pacificresearch.org www.nanotechnologynow.com www.metamateria.com www.ioew.de www.wikipedia.com