Mechatronics is the synergistic combination of mechanical
engineering, electronics, controls engineering, and computers ...
Mechatronics is adding intelligence to a mechanical designs. 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.
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
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.
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.
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 scienti ic understanding
towards f 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 nanotechnolog During y. 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 they would stick 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
wa When two y.
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 preceding stage and resulting,
if
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 active 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 automot ive
and transportation industry. In Automobiles, 1. Micro chips
regulate 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 techn
ical 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