pecmec`15 1 - Panimalar Engineering College

PECMEC’15
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NANOROBOTICS
Nanorobotics is the emerging technology field creating machines or robots whose
components are at or close to the scale of a nanometer (10−9 meters). More specifically,
nanorobotics refers to the nanotechnology engineering discipline of designing and building
nanorobots, with devices ranging in size from 0.1–10 micrometers and constructed of
nanoscale or molecular components.[4][5] The names nanobots, nanoids, nanites,
nanomachines, or nanomites have also been used to describe these devices currently
under research and development.
Nanomachines are largely in the research-and-development phase, but some primitive
molecular machines and nanomotors have been tested. An example is a sensor having a
switch approximately 1.5 nanometers across, capable of counting specific molecules in a
chemical sample. The first useful applications of nanomachines might be in medical
technology, which could be used to identify and destroy cancer cells.
Marching of Medical Nano-Robots
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Another potential application is the detection of toxic chemicals, and the measurement of
their concentrations, in the environment. Rice University has demonstrated a singlemolecule car developed by a chemical process and including buckyballs for wheels. It is
actuated by controlling the environmental temperature and by positioning a scanning
tunneling microscope tip.
Another definition is a robot that allows precision interactions with nanoscale objects, or
can manipulate with nanoscale resolution. Such devices are more related to microscopy or
scanning probe microscopy, instead of the description of nanorobots as molecular
machine. Following the microscopy definition even a large apparatus such as an atomic
force microscope can be considered a nanorobotic instrument when configured to perform
nanomanipulation. For this perspective, macroscale robots or microrobots that can move
with nanoscale precision can also be considered nanorobots.
Nanorobotics theory
According to Richard Feynman, it was his former graduate student and collaborator Albert
Hibbs who originally suggested to him (circa 1959) the idea of a medical use for
Feynman's theoretical micromachines (see nanotechnology). Hibbs suggested that certain
repair machines might one day be reduced in size to the point that it would, in theory, be
possible to (as Feynman put it) "swallow the doctor". The idea was incorporated into
Feynman's 1959 essay There's Plenty of Room at the Bottom.
Since nanorobots would be microscopic in size, it would probably be necessary for very
large numbers of them to work together to perform microscopic and macroscopic tasks.
These nanorobot swarms, both those incapable of replication (as in utility fog) and those
capable of unconstrained replication in the natural environment (as in grey goo and its less
common variants, are found in many science fiction stories, such as the Borg nanoprobes
in Star Trek and The Outer Limits episode The New Breed.
Some proponents of nanorobotics, in reaction to the grey goo scenarios that they earlier
helped to propagate, hold the view that nanorobots capable of replication outside of a
restricted factory environment do not form a necessary part of a purported productive
nanotechnology, and that the process of self-replication, if it were ever to be developed,
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could be made inherently safe. They further assert that their current plans for developing
and using molecular manufacturing do not in fact include free-foraging replicators.
The most detailed theoretical discussion of nanorobotics, including specific design issues
such as sensing, power communication, navigation, manipulation, locomotion, and
onboard computation, has been presented in the medical context of nanomedicine by
Robert Freitas. Some of these discussions remain at the level of unbuildable generality and
do not approach the level of detailed engineering.
Biochip
The joint use of nanoelectronics, photolithography, and new biomaterials provides a
possible approach to manufacturing nanorobots for common medical applications, such as
for surgical instrumentation, diagnosis and drug delivery.[15][16][17] This method for
manufacturing on nanotechnology scale is currently in use in the electronics industry. So,
practical nanorobots should be integrated as nanoelectronics devices, which will allow
tele-operation and advanced capabilities for medical instrumentation.
Nubots
Nubot is an abbreviation for "nucleic acid robot." Nubots are organic molecular machines
at the nanoscale. DNA structure can provide means to assemble 2D and 3D
nanomechanical devices. DNA based machines can be activated using small molecules,
proteins and other molecules of DNA. Biological circuit gates based on DNA materials
have been engineered as molecular machines to allow in-vitro drug delivery for targeted
health problems. Such material based systems would work most closely to smart
biomaterial drug system delivery, while not allowing precise in vivo teleoperation of such
engineered prototypes.
Surface-bound systems
A number of reports have demonstrated the attachment of synthetic molecular motors to
surfaces. These primitive nanomachines have been shown to undergo machine-like
motions when confined to the surface of a macroscopic material. The surface anchored
motors could potentially be used to move and position nanoscale materials on a surface in
the manner of a conveyor belt.
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Positional nanoassembly
Nanofactory Collaboration, founded by Robert Freitas and Ralph Merkle in 2000 and
involving 23 researchers from 10 organizations and 4 countries, focuses on developing a
practical research agenda specifically aimed at developing positionally-controlled diamond
mechanosynthesis and a diamondoid nanofactory that would have the capability of
building diamondoid medical nanorobots.
Bacteria-based
This approach proposes the use of biological microorganisms, like the bacterium
Escherichia coli. Thus the model uses a flagellum for propulsion purposes.
Electromagnetic fields normally control the motion of this kind of biological integrated
device. Chemists at the University of Nebraska have created a humidity gauge by fusing a
bacteria to a silicone computer chip.
Virus-based
Retroviruses can be retrained to attach to cells and replace DNA. They go through a
process called reverse transcription to deliver genetic packaging in a vector. Usually, these
devices are Pol - Gag genes of the virus for the Capsid and Delivery system. This process
is called retroviral Gene Therapy, having the ability to re-engineer cellular DNA by usage
of viral vectors. This approach has appeared in the form of Retroviral, Adenoviral, and
Lentiviral gene delivery systems. These Gene Therapy vectors have been used in cats to
send genes into the genetic modified animal "GMO" causing it display the trait.
Open technology
A document with a proposal on nanobiotech development using open technology
approaches has been addressed to the United Nations General Assembly. According to the
document sent to the UN, in the same way that Open Source has in recent years
accelerated the development of computer systems, a similar approach should benefit the
society at large and accelerate nanorobotics development. The use of nanobiotechnology
should be established as a human heritage for the coming generations, and developed as an
open technology based on ethical practices for peaceful purposes. Open technology is
stated as a fundamental key for such an aim.
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Nanorobot race
In the same ways that technology development had the space race and nuclear arms race, a
race for nanorobots is occurring. There is plenty of ground allowing nanorobots to be
included among the emerging technologies. Some of the reasons are that large
corporations, such as General Electric, Hewlett-Packard, Synopsys, Northrop Grumman
and Siemens have been recently working in the development and research of nanorobots;
surgeons are getting involved and starting to propose ways to apply nanorobots for
common medical procedures;[50] universities and research institutes were granted funds by
government agencies exceeding $2 billion towards research developing nanodevices for
medicine; bankers are also strategically investing with the intent to acquire beforehand
rights and royalties on future nanorobots commercialization. Some aspects of nanorobot
litigation and related issues linked to monopoly have already arisen. A large number of
patents has been granted recently on nanorobots, done mostly for patent agents, companies
specialized solely on building patent portfolio, and lawyers. After a long series of patents
and eventually litigations, see for example the Invention of Radio or about the War of
Currents, emerging fields of technology tend to become a monopoly, which normally is
dominated by large corporations.
Potential applications
Nanomedicine
Potential applications for nanorobotics in medicine include early diagnosis and targeted
drug-delivery for cancer, biomedical instrumentation, surgery, pharmacokinetics
monitoring of diabetes and health care.
In such plans, future medical nanotechnology is expected to employ nanorobots injected
into the patient to perform work at a cellular level. Such nanorobots intended for use in
medicine should be non-replicating, as replication would needlessly increase device
complexity, reduce reliability, and interfere with the medical mission.
Nanotechnology provides a wide range of new technologies for developing customized
solutions that optimize the delivery of pharmaceutical products. Today, harmful side
effects of treatments such as chemotherapy are commonly a result of drug delivery
methods that don't pinpoint their intended target cells accurately. Researchers at Harvard
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and MIT, however, have been able to attach special RNA strands, measuring nearly 10 nm
in diameter, to nano-particles, filling them with a chemotherapy drug. These RNA strands
are attracted to cancer cells. When the nanoparticle encounters a cancer cell, it adheres to
it, and releases the drug into the cancer cell. This directed method of drug delivery has
great potential for treating cancer patients while avoiding negative effects (commonly
associated with improper drug delivery). The first demonstration of nanomotors operating
in living organism was carried out in 2014 at UCSD, San Diego.
Another useful application of nanorobots is assisting in the repair of tissue cells alongside
white blood cells. The recruitment of inflammatory cells or white blood cells (which
include neutrophils, lymphocytes, monocytes and mast cells) to the affected area is the
first response of tissues to injury. Because of their small size nanorobots could attach
themselves to the surface of recruited white cells, to squeeze their way out through the
walls of blood vessels and arrive at the injury site, where they can assist in the tissue repair
process. Certain substances could possibly be utilized to accelerate the recovery.
The science behind this mechanism is quite complex. Passage of cells across the blood
endothelium, a process known as transmigration, is a mechanism involving engagement of
cell surface receptors to adhesion molecules, active force exertion and dilation of the
vessel walls and physical deformation of the migrating cells. By attaching themselves to
migrating inflammatory cells, the robots can in effect “hitch a ride” across the blood
vessels, bypassing the need for a complex transmigration mechanism of their own.
The US FDA currently regulates nanotechnology on the basis of size. The FDA also
regulates that which acts by chemical means as a drug, and that which acts by physical
means as a device. Single molecules can also be used as Turing machines, like their larger
paper tape counterparts, capable of universal computation and exerting physical (or
chemical) forces as a result of that computation. Safety systems are being developed so
that if a drug payload were to be accidentally released, the payload would either be inert or
another drug would be then released to counteract the first. Toxicological testing becomes
convolved with software validation in such circumstances. With new advances in
nanotechnology these small devices are being created with the ability to self-regulate and
be ‘smarter’ than previous generations.
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As nanotechnology becomes more complex, how will regulatory agencies distinguish a
drug from a device. Drug molecules must undergo slower and more expensive testing (for
example, preclinical toxicological testing) than devices, and the regulatory pathways for
devices are simpler than for drugs. Perhaps smartness, if smart enough, will someday be
used to justify a device classification for a single molecule nanomachine. Devices are
generally approved more quickly than drugs, so device classification could be beneficial to
patients and manufacturers.
Nanolithography
Nanolithography is the branch of nanotechnology concerned with the study and
application of fabricating nanometer-scale structures, meaning patterns with at least one
lateral dimension between the size of an individual atom and approximately 100 nm.
Nanolithography is used during the fabrication of leading-edge semiconductor integrated
circuits (nanocircuitry) or nanoelectromechanical systems (NEMS). As of 2015,
nanolithography is a very active area of research in academia and in industry.
Optical lithography
Optical lithography, which has been the predominant patterning technique since the advent
of the semiconductor age, is capable of producing sub-100-nm patterns with the use of
very short wavelengths (currently 193 nm). Optical lithography will require the use of
liquid immersion and a host of resolution enhancement technologies (phase-shift masks
(PSM), optical proximity correction (OPC)) at the 32 nm node. Most experts feel that
traditional optical lithography techniques will not be cost effective below 22 nm. At that
point, it may be replaced by a next-generation lithography (NGL) technique. A new one,
Quantum Optical Lithography announced a resolution of 2 nm half-pitch lines at SPIE
Advanced Lithography 2012.
APPLICATIONS OF NANOLITHOGRAPHY
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Miniaturization of FET
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Surface gated quantum devices
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Quantum dots
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Wires
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Grating
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
Zone plates
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Mask making
Other nanolithography techniques
X-ray lithography can be extended to an optical resolution of 15 nm by using the
short wavelengths of 1 nm for the illumination. This is implemented by the
proximity printing approach. The technique is developed to the extent of batch
processing. The extension of the method relies on Near Field X-rays in Fresnel
diffraction: a clear mask feature is "demagnified" by proximity to a wafer that is
set near to a "Critical Condition". This Condition determines the mask-to-wafer
Gap and depends on both the size of the clear mask feature and on the wavelength.
The method is simple because it requires no lenses.
Double patterning is a method of increasing the pitch resolution of a lithographic
process by printing new features in between pre-printed features on the same layer.
It is flexible because it can be adapted for any exposure or patterning technique.
The feature size is reduced by non-lithographic techniques such as etching or
sidewall spacers. It has been used in commercial production of microprocessors
since the 32nm process node. "Multiple Patterning" is expected to be used in future
process nodes, until next generation lithography technologies become practical.
Work is in progress on an optical maskless lithography tool. This uses a digital
micro-mirror array to directly manipulate reflected light without the need for an
intervening mask. Throughput is inherently low, but the elimination of maskrelated production costs - which are rising exponentially with every technology
generation - means that such a system might be more cost effective in the case of
small production runs of state of the art circuits, such as in a research lab, where
tool throughput is not a concern.
The most common nanolithographic technique is Electron-Beam Direct-Write
Lithography (EBDW), the use of a beam of electrons to produce a pattern —
typically in a polymeric resist such as PMMA.
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Extreme ultraviolet lithography (EUV) is a form of optical lithography using
ultrashort wavelengths (13.5 nm). It is the most popularly considered NGL
technique.
Laser Printing of Single Nanoparticles In this method, the optical forces induced
via scattering and absorption of photons on nanoparticles are used to direct single
nanoparticles to specific locations on substrates and attach them via van-der Waals
forces. This technique has been demonstrated on metallic nanoparticles, which are
easier to print due to their large plasmonically-induced scattering and absorption
cross sections, in both serial and parallel printing methods.
Charged-particle lithography, such as ion- or electron-projection lithographies
(PREVAIL, SCALPEL, LEEPL), are also capable of very-high-resolution
patterning. Ion beam lithography uses a focused or broad beam of energetic
lightweight ions (like He+) for transferring pattern to a surface. Using Ion Beam
Proximity Lithography (IBL) nano-scale features can be transferred on non-planar
surfaces.
Neutral Particle Lithography(NPL) uses a broad beam of energetic neutral
particle for pattern transfer on a surface.
Nanoimprint lithography (NIL), and its variants, such as Step-and-Flash Imprint
Lithography, LISA and LADI are promising nanopattern replication technologies.
This technique can be combined with contact printingand cold welding.
Scanning probe lithography (SPL) is a promising tool for patterning at the deep
nanometer-scale. For example, individual atoms may be manipulated using the tip
of a scanning tunneling microscope (STM). Dip-Pen Nanolithography (DPN) is the
first commercially available SPL technology based on atomic force microscopy.
Atomic Force Microscopic Nanolithography (AFM) is a chemomechanical
surface patterning technique that uses an atomic force microscope.
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Thermochemical Nanolithography (TCNL) is an atomic force microscopy based
technique, which uses hot tips to activate chemical reactions at the nanoscale. it was used
to create arrays of proteins, DNA, graphene-like nanostructures, PPV nanowires, and
piezoelectric nanoarrays.
Magnetolithography (ML) based on applying a magnetic field on the substrate using
paramagnetic metal masks call "magnetic mask". Magnetic mask which is analog to
photomask define the spatial distribution and shape of the applied magnetic field. The
second component is ferromagnetic nanoparticles (analog to the photoresist) that are
assembled onto the substrate according to the field induced by the magnetic mask.
Bottom-up methods
Nanosphere lithography uses self-assembled monolayers of spheres (typically made of
polystyrene) as evaporation masks. This method has been used to fabricate arrays of gold
nanodots with precisely controlled spacings.
It is possible that molecular self-assembly methods will take over as the primary
nanolithography approach, due to ever-increasing complexity of the top-down approaches
listed above. Self-assembly of dense lines less than 20 nm wide in large pre-patterned
trenches has been demonstrated. The degree of dimension and orientation control as well
as prevention of lamella merging still need to be addressed for this to be an effective
patterning technique. The important issue of line edge roughness is also highlighted by this
technique.
Self-assembled ripple patterns and dot arrays formed by low-energy ion-beam sputtering
are another emerging form of bottom-up lithography. Aligned arrays of plasmonic and
magnetic wires and nanoparticles are deposited on these templates via oblique
evaporation. The templates are easily produced over large areas with periods down to
25 nm.
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Immersion lithography
Immersion lithography is a photolithography resolution enhancement technique for
manufacturing integrated circuits (ICs) that replaces the usual air gap between the final
lens and the wafer surface with a liquid medium that has a refractive index greater than
one. The resolution is increased by a factor equal to the refractive index of the liquid.
Current immersion lithography tools use highly purified water for this liquid, achieving
feature sizes below 45 nanometers. ASML, Canon, and Nikon are currently the only
manufacturers of immersion lithography systems. The idea for Immersion lithography
was first proposed and realized in the 1980s.
3D Printing Technology
Introduction to 3D Printing
3D printing is a form of additive manufacturing technology where a three dimensional
object is created by laying down successive layers of material. It is also known as rapid
prototyping, is a mechanized method whereby 3D objects are quickly made on a
reasonably sized machine connected to a computer containing blueprints for the object.
The 3D printing concept of custom manufacturing is exciting to nearly everyone. This
revolutionary method for creating 3D models with the use of inkjet technology saves time
and cost by eliminating the need to design; print and glue together separate model parts.
Now, you can create a complete model in a single process using 3D printing. The basic
principles include materials cartridges, flexibility of output, and translation of code into a
visible pattern.
Typical 3D Printer
3D Printers are machines that produce physical 3D models from digital data by
printing layer by layer. It can make physical models of objects either designed with a
CAD program or scanned with a 3D Scanner. It is used in a variety of industries
including jewelry, footwear, industrial design, architecture, engineering and
construction, automotive, aerospace, dental and medical industries, education and
consumer products.
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History of 3d Printing
The technology for printing physical 3D objects from digital data was first developed
by Charles Hull in 1984. He named the technique as Stereo lithography and obtained
a patent for the technique in 1986. While Stereo lithography systems had become
popular by the end of 1980s, other similar technologies such as Fused Deposition
Modeling (FDM) and Selective Laser Sintering (SLS) were introduced.
In 1993, Massachusetts Institute of Technology (MIT) patented another technology,
named "3 Dimensional Printing techniques", which is similar to the inkjet technology
used in 2D Printers. In 1996, three major products, "Genisys" from Stratasys, "Actua
2100" from 3D Systems and "Z402" from Z Corporation, were introduced. In 2005, Z
Corp. launched a breakthrough product, named Spectrum Z510, which was the first
high definition color 3D Printer in the market. Another breakthrough in 3D Printing
occurred in 2006 with the initiation of an open source project, named Reprap, which
was aimed at developing a selfreplicating 3D printer.
MANUFACTURING A MODEL WITH THE 3D PRINTER
The model to be manufactured is built up a layer at a time. A layer of powder is
automatically deposited in the model tray. The print head then applies resin in the
shape of the model. The layer dries solid almost immediately. The model tray then
moves down the distance of a layer and another layer of power is deposited in
position, in the model tray. The print head again applies resin in the shape of the
model, binding it to the first layer. This sequence occurs one layer at a time until the
model is complete
Very recently Engineers at the University of Southampton in the UK have designed,
printed, and sent skyward the world’s first aircraft manufactured almost entirely via
3-D printing technology. The UAV dubbed SULSA is powered by an electric motor
that is pretty much the only part of the aircraft not created via additive
manufacturing methods.
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World’s First 3D Printed Plane Takes Flight
Created on an EOS EOSINT P730 nylon laser sintering machine, its wings, hatches
and control surfaces basically everything that makes up its structure and
aerodynamic controls was custom printed to snap together. It requires no fasteners
and no tools to assemble.
Current 3D Printing Technologies
Stereo lithography - Stereo lithographic 3D printers (known as SLAs or stereo
lithography apparatus) position a perforated platform just below the surface of a vat
of liquid photo curable polymer. A UV laser beam then traces the first slice of an
object on the surface of this liquid, causing a very thin layer of photopolymer to
harden. The perforated platform is then lowered very slightly and another slice is
traced out and hardened by the laser. Another slice is then created, and then another,
until a complete object has been printed and can be removed from the vat of
photopolymer, drained of excess liquid, and cured.
Fused deposition modelling - Here a hot thermoplastic is extruded from a
temperature-controlled print head to produce fairly robust objects to a high degree
of accuracy.
Selective laser sintering (SLS) - This builds objects by using a laser to selectively
fuse together successive layers of a cocktail of powdered wax, ceramic, metal, nylon
or one of a range of other materials.
Multi-jet modelling (MJM) - This again builds up objects from successive layers of
powder, with an inkjet-like print head used to spray on a binder solution that glues
only the required granules together.
The VFlash printer, manufactured by Canon, is low-cost 3D printer. It’s known to
build layers with a light-curable film. Unlike other printers, the VFlash builds its parts
from the top down.
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Desktop Factory is a startup launched by the Idealab incubator in Pasadena,
California.
Fab@home, an experimental project based at Cornell University, uses a syringe to
deposit material in a manner similar to FDM. The inexpensive syringe makes it easy
to experiment with different materials from glues to cake frosting.
The Nanofactory 3D printing technologies are introduced that are related to the
nanotechnologies.
3D Printing Capabilities:
As anticipated, this modern technology has smoothed the path for numerous new
possibilities in various fields. The list below details the advantages of 3D printing in
certain fields.
1. Product formation is currently the main use of 3D printing technology. These
machines allow designers and engineers to test out ideas for dimensional products
cheaply before committing to expensive tooling and manufacturing processes.
2. In Medical Field, Surgeons are using 3d printing machines to print body parts for
reference before complex surgeries. Other machines are used to construct bone
grafts for patients who have suffered traumatic injuries. Looking further in the
future, research is underway as scientists are working on creating replacement
organs.
3. Architects need to create mockups of their designs. 3D printing allows them to
come up with these mockups in a short period of time and with a higher degree of
accuracy.
4. 3D printing allows artists to create objects that would be incredibly difficult, costly,
or time intensive using traditional processes.
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3D Saves Time and Cost
Creating complete models in a single process using 3D printing has great benefits.
This innovative technology has been proven to save companies time, manpower and
money. Companies providing 3D printing solutions have brought to life an efficient
and competent technological product.
SELF-VENTILATING BUILDING SKIN WITH SMART THERMOBIMETALS
Challenging the traditional presumption that a building skin should be static and
inanimate, this investigation examines the replacement of this convention with a responsive system that is a prosthetic extension of man and a mediator for the environment.
With the emergence of smart materials, an elevated interest in utilizing unconventional
building systems and an urgent need to build sustainable structures, our buildings can be
more sensitive to the environment and the human body, raising the level of effectiveness
while altering our perception of enclosure. To test this thesis, an 8’ tall portable prototype
with a responsive, self-ventilating building skin using sheet thermobimetal, a smart
material never before used in building skins, was built. By laminating two metal alloys
with different coefficients of expansion together, the result is a thermobimetal that curls
when heated and flattens when cooled. As the temperature rises, this deformation will
allow the building skin to breathe much like the pores in human skin.
Even during the modern movement, exterior walls were designed to be static and rigid.
Visual access between interior and exterior environments was open with the use of glass and
steel, but artificial climate control still determined the impenetrable limits of those glass
walls. As times change, more recent public interest in sustainable design, energy
conservation and zero-emission building design has infused the industry with renewed
impetus to seek alternative solutions. With the emergence of new smart materials, the
evolution of digital technologies and the availability of mass-customization methods, those
same walls can now be designed to be responsive, interactive and even porous, much like
human skin. As a “third” skin (the “first” being human skin, the “second” clothing),
architecture can, in effect, bring us closer to nature by elevating the sensitivity of the building
surfaces. This research challenges the traditional notions and demonstrates that these
surfaces can breathe and self-ventilate without the need of a costly energy source.
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Self-Ventilating Building Skin
Thermobimetals: A Smart Material for Building Skins
Once merely an element to build shelter, materiality has now become instrumental in
the design of building skins. The experimental attitude to materiality has architects
considering the use of materials in new and unexpected ways, in unconventional
situations and conditions. Many of these newly developed materials are capable of
reacting flexibly to the external conditions physically or chemically in response to
changes in the temperature, light, electric field or movement. The term Smart
Materials has been used to define these materials that have changeable properties
and are able to reversibly change their shape or color. These materials are important
to architectural skins in that they allow the building surface to be reactive to changes,
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both inside and out, automatically. “Energy and matter flows can be optimized
through the use of smart materials, as the majority of these materials and products
take up energy and matter indirectly and directly from the environment.”ii This
multifaceted investigation focuses on the development of an old industrial smart
material used in a completely innovative application—for architectural skins.
Thermobimetals have been used since the beginning of the industrial revolution. A
lamination of two metals together with different thermal expansion coefficients, it
simply deforms when heated or cooled. As the temperature rises, one side of the
laminated sheet will expand more than the other. The result will be a curved or
curled piece of sheet metal. Reacting with outside temperatures, this smart material
has the potential to develop self-actuating intake or exhaust for facades. Available in
the form of strips, disks or spirals, thermobimetals are commonly used today in
thermostats as a measurement and control system and in electrical controls as
components in mechatronic systems. So far, however, few applications in
architecture have been documented. Automatically opening and closing ventilation
flaps have been developed and installed in greenhouses and for use as self-closing
fire protection flaps, but nothing has been published on the development of this
material for building skins.
Thermobimetals can be a combination of any two compatible sheet metals. The
combinations of metals with different expansion coefficients and at various
thicknesses can produce a wide range of deflection. TM2, the ideal thermobimetal for
this investigation, had the highest amount of deflection in the temperature range of
0-120 degrees Fahrenheit. The low expansion material is called Invar, which is an
alloy of 64% iron and 36% nickel with some carbon and chromium. The high
expansion material is a nickel manganese alloy composed of 72% manganese, 18%
copper and 10% nickel. This bi-metal is also called 36-10 and the ASTM name is TM2.
Made corrosion-resistant by plating with chrome and copper, this material is
available in sheets or strips in several thicknesses. It can be fabricated into disks,
spirals and other shapes. The amount of deflection varies dependent on the size of
the sheet, the air temperature, the position of clamping and the thickness of the
material. The thickness selected for this study is 0.010”
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Building Technologies: Detailing, Structure and Assembly
Because this study focused on thermobimetals as a building material, it was
important to retain the integrity of the material and not add other unnecessary
materials to the assembly. Like sheets of steel and aluminum, this material could be
easily laser-cut and readily handled. Various thicknesses of materials were tested for
strength, pliability, weight and curvature before the final gauge of 0.010” was
selected, a thickness similar to aluminum flashing. Because the material was
manufactured in rolls of 12”wide, this dimension determined the largest-sized pieces
that could be cut from the metal sheets. A system of tiles, ranging from 2” to 12” long,
was designed with connection details of tabs and slots, eliminating the need for
added material. The horizontal connection of tabs/slots allowed movement along the
slots up and down during assembly, but restricted the horizontal movement once in
place. This restriction would limit the movement of the system to only allow the
temperature to change the form when the individual tiles curved. The vertical connections, on the other hand, were designed with very little tolerances. These areas
needed to provide structural tension by gravity. Again, horizontal movement had to
be limited.
Using this tab/slot system, it was critical to design a surface that was taut when cold,
with no openings. When the temperature was cold, the skin would clamp down and
prevent air passage through the pores. After numerous studies, a weave system of
simple cross-shaped tiles was selected. This shape would accommodate both
horizontally- and vertically-biased tiles. Horizontal tiles (12”wide x 2”tall)
congregated on one side while vertical ones (2”wide x 12”tall) grouped on the other
side. The full range was incorporated to test the capabilities relative to gravity,
friction and other resistant forces.
The structural system was integral to the surface weave design. The bell-shaped form
hung upside-down eliminated the need for any additional structure. Because the
form followed a catenary curve, it was able to support its own weight. Hung from a 9’
diameter aluminum ring with pink silk string, the prototype at 8’ tall weighed under
80 pounds.
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The thermobimetal is proving to have huge potential as a building material,
especially as one that can be responsive to temperature change. There are, however,
a few unanticipated problems learned from this exercise, that, although not
insurmountable, must be addressed at this stage. The most obvious problem is that
the ideal operating temperature range for the prototype is about 100-120 degrees
Fahrenheit. Although the individual tiles demonstrate and the engineered data
calculates the material to curl at a range of 70-100 degrees, the tiles perform differently when assembled in a weave. There are two potential solutions to this problem.
The first is changing the actual alloys that are being laminated to ones that are more
sensitive to temperature change at lower ranges. A larger differential between the
two sides would possibly enhance the sensitivity. The other possible solution is to
enhance the performance of the present material by adding more materials to the
wall assembly. Adding a heat absorbing material on the outside and a temperature
insulating material on the inside, the rate of reaction of the two opposing sides of the
laminated metal sheet will be increased. The sheet metal will curve at a lower
temperature and with more deflection. Different materials are being considered such
as Super Blackiv, a nanocoating that absorbs 99.6% of light and heat, and Aerogelv, a
featherweight insulating nanomaterial. The final system is optimally intended to be
lightweight, high-tech and fully operational at 80 degrees.
The thermobimetal is proving to have huge potential as a building material,
especially as one that can be responsive to temperature change. There are, however,
a few unanticipated problems learned from this exercise, that, although not
insurmountable, must be addressed at this stage. The most obvious problem is that
the ideal operating temperature range for the prototype is about 100-120 degrees
Fahrenheit. Although the individual tiles demonstrate and the engineered data
calculates the material to curl at a range of 70-100 degrees, the tiles perform differently when assembled in a weave. There are two potential solutions to this problem.
The first is changing the actual alloys that are being laminated to ones that are more
sensitive to temperature change at lower ranges. A larger differential between the
two sides would possibly enhance the sensitivity. The other possible solution is to
enhance the performance of the present material by adding more materials to the
wall assembly. Adding a heat absorbing material on the outside and a temperature
insulating material on the inside, the rate of reaction of the two opposing sides of the
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PECMEC’15
laminated metal sheet will be increased. The sheet metal will curve at a lower
temperature and with more deflection. Different materials are being considered such
as Super Blackiv, a nanocoating that absorbs 99.6% of light and heat, and Aerogelv, a
featherweight insulating nanomaterial. The final system is optimally intended to be
lightweight, high-tech and fully operational at 80 degrees.
Requiring very little skill by design, the assembly process results in few problems.
Despite one minor difficulty in the flexibility of the smallest pieces, especially when
inserting the tabs into the tiny slots, assembly time takes a swift 16 hours for four
people. The size-to-flexibility ratio is most pliable at larger sizes, allowing the tiles to
bend without deformation during assembly. Some of the smaller pieces are too small
for human hands to manipulate with any kind of facility. The scale of the smaller tiles
need to be increased to allow easier handling.
Finally, more attention must be paid to the fabrication, shipping and storage of the
raw material. The material is delivered rolled in the opposite direction of the heated
curve. Although the reverse curve can serendipitously keep the prototype’s surface
taut when cold, it may not be the ideal original form. In the case of the prototype, as
the temperature rises, the material reverses its curve and makes a loud clicking
sound. Not completely useless, this sound can be a design element and exaggerated. If
unwanted, manufacturing of the raw material and special specifications must be
predetermined with the manufacturer.
Top 10 Innovations in Automobile Industry in 2014 …
1. Google Driverless Cars
On the onset of winter break, on December 23, Google announced its
first fully functional driverless car, which is ready for testing on public
roads. Prior to this, the Internet giant developed various prototypes that
lacked on different fundamental and functional aspects.
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The latest prototype has all the important elements like headlights, steering and brakes.
The company have also created a self-driving system with sensors and computers that
can be fitted to SUVs like Lexus. This new technology will not only be a breakthrough in
tough traffic congestion but sensing technology can also increase road safety. Countries
such as the UK and US are working on laws to allow driverless cars.
2.Automated Manual Transmission (AMT)
In the 2014 Delhi Auto Expo, where more than 70 vehicles were launched, one that
pundits hailed as the most important was Maruti Suzuki's Celerio, the first affordable
mass segment gearless hatchback. Celerio comes with AMT(automate manual
transmission) sourced from Magneti Marelli, component arm of Fiat. AMT is an electrohydraulic mechanism to automate manual transmission, which derives from Formula 1.
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It has a hydraulic system and an electronic system. The electronic transmission control
Unit helps in engaging and disengaging the clutch and gear through electronic actuator.
It also has a sports mode, which enables drivers to move to the manual shifting of gear
to increase and decrease the gear ratios with plus and minus either through gear knob
/joystick or the steering. In India, AMT is currently available in three cars — Celerio,
Alto K10 and Tata Zest.
3. V2V Communications
In February, US National Highway Traffic Safety Administration announced that it will
begin taking steps to enable vehicle-to-vehicle (V2V) communication technology for
light vehicles. This technology allow vehicles to "talk" to each other & ltimately avoid
many crashes altogether by exchanging basic safety data, such as speed and position,
ten times per second, to improve safety.
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PECMEC’15
It uses 'ad hoc network', where every car is free to associate with any other car
available in the network and share equal status. V2V, which is also known as VANET
(vehicular ad hoc network),is a variation of MANET (mobile ad hoc network). Many
automobile manufacturers including are BMW, Audi, Honda, General Motors, Volvo and
Daimler working and developing this technology to improve safety, overcome blind
spots and avoid accidents.
4.Pre-CollisionTechnology
Top carmakers such as Ford and Hyundai have developed a pre-collision assist and
Pedestrian detection technology. Besides helping the driver detect blind spots, this
technology also alerts the driver when he/she is not paying attention on the road. And
if the driver falls asleep and does not respond to the warning, then the system applies
the brakes on its own. The driver assist system has two types of sensors.
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PECMEC’15
One is millimetre-wave radar located inside the front grille, and the other is a
monocular camera mounted on the upper, inside part of the windshield. Its collision
mitigation braking system delivers an audio and visual warning when there is a risk of a
head-on collision. If the driver fails to react, the car will automatically begin breaking
itself to prevent or reduce the severity of a crash. This technology will debut in 2015
with Ford Mondeo in Europe. Hyundai would introduce it in the new Genesis sedan.
5. Smart Car
After smartphones, we will soon have smart cars around. In June 2014, Google
launched its 'Android Auto', a telematics software that can be connected to car dash
board for infotainment. It also enables the driver to access GPS, maps, streaming music,
weather, and a host of other applications. A slew of carmakers including Abarth, Acura,
Alfa Romeo, Audi, Bentley, Chevrolet, Chrysler, Dodge, Fiat, Ford, Infiniti, Jeep, Kia,
Maserati and Volvo will offer Android Auto in their cars
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Earlier, at the Geneva Motor Show in March, Apple announced its 'CarPlay' software,
which allows devices running on the iOS operating system to function with built-in
display units of automobile dashboards. Carmakers like BMW, Daimler, JLR, Honda and
Hyundai have installed it in their cars. Infotainment manufacturers like Pioneer & Alpine
too have shown interest in Carplay from Apple.
6. Ford Aluminium Track
In 2014, Ford unveiled the first aluminium-bodied full-size pickup, rolling out aluminium
version of its popular F-150 from its Dearborn plant. It is 700 pounds or about 318 kg
lighter than the steel-bodied version, making it a more fuel-efficient and nimbler
pickup.
The F-150 has been the best-selling vehicle in the US for 32 straight years. Last year,
Ford sold nearly 100,000 more full-size pickups than General Motors. Aluminium isn't
new to the auto industry, but this is the first time it will cover the entire body of such a
high-volume vehicle.
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7. Start- Stop Technology
Hero MotoCorp introduced its first bike with start-stop technology, Splendor iSmart, in
March 2014. The company calls it i3s technology which is also known as Idle Start and
Stop System. i3s is a green technology that automatically shuts the engine when idling
and turns it on, when needed, with a simple press of the clutch, giving more mileage in
congested cities.
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8. Bus Powered by Human Waste
In November, the world witnessed the first ever bus to run on human waste on the
roads of Britain. According to researchers, the bus can provide a sustainable way of
fuelling public transport — cutting emissions in polluted towns and cities.
The 40-seater Bio-Bus, which runs on gas generated through the treatment of sewage
and food waste, helps to improve urban air quality as it produces fewer emissions than
traditional diesel engines. The bus can travel up to 300 km on a full tank of gas.
9. Land Rover's Invisible Car
In April, Tata -owned JLR introduced a new technology to give drivers a digital vision of
the terrain ahead by making the front of the car 'virtually' invisible. The technology —
named Transparent Bonnet — enables a driver climbing a steep incline or manoeuvring
in a confined space to see an augmented reality view capturing not only the terrain in
front of the car but also the angle and position of the front wheels.
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The cameras located in the vehicle's grille capture data used to feed a head-up display,
effectively creating a 'see-through' view of the terrain through the bonnet and engine
bay, breaking new ground in visual driver assistance.
10. Toyota's Hovering Car
Toyota is developing a future airborne car. A media report quoted Hiroyoshi Yoshiki,
managing officer at Toyota Motor Corporation, as saying the company has been toying
with the idea of flying cars.
The concept car being developed at one of Toyota's high tech R&D centres won't be
actually flying around, but instead would be floating slightly above the road to reduce
friction, a bit like a hovercraft. This is just a case-study and the actual Toyota hovering
car may not make it to the showrooms anytime in the near future.
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Space debris
Space debris, also known as orbital debris, space junk and space waste, is the
collection of defunct objects in orbit around Earth. This includes spent rocket stages, old
satellites and fragments from disintegration, erosion and collisions. Since orbits overlap
with new spacecraft, debris may collide with operational spacecraft.
As of 2009 about 19,000 pieces of debris larger than 5 cm (2 in) are tracked, with 300,000
pieces larger than 1 cm estimated to exist below 2,000 kilometres (1,200 mi). For
comparison, the International Space Station orbits in the 300–400 kilometres (190–250 mi)
range and the 2009 satellite collision and 2007 antisat test events occurred at from 800 to
900 kilometres (500 to 560 mi).
Most space debris is smaller than 1 cm (0.4 in), including dust from solid rocket motors,
surface-degradation products (such as paint flakes) and frozen coolant droplets released
from RORSAT nuclear-powered satellites. Impacts by these particles cause erosive
damage, similar to sandblasting, which can be reduced by the addition of ballistic
shielding (such as a Whipple shield, used to protect parts of the International Space
Station) to a spacecraft. Not all parts of a spacecraft can be protected in this manner; solar
panels and optical devices such as telescopes or star trackers are subject to constant wear
from debris and micrometeoroids. Below 2,000 kilometres (1,200 mi), the flux from space
debris is greater than that from meteoroids. Decreasing risk from space debris larger than
10 cm (4 in) is often obtained by maneuvering a spacecraft to avoid a collision. If a
collision occurs, the resulting fragments can become an additional collision risk.
Since the chance of collision is influenced by the number of objects in space, there is a
critical density where the creation of new debris is theorized to occur faster than natural
forces remove them. Beyond this point a runaway chain reaction (known as the Kessler
syndrome) may occur, rapidly increasing the amount of debris in orbit and the risk to
operational satellites. Whether the critical density has been reached in certain orbital bands
is a subject of debate. A Kessler syndrome would render a portion of useful polar-orbiting
bands difficult to use, increasing the cost of space missions. The measurement, growth
mitigation and removal of space debris are conducted by the space industry.
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Space debris seen from outside geosynchronous orbit (GEO). Note the two primary
debris fields, the ring of objects in GEO and the cloud of objects in low Earth orbit (LEO).
Most space debris consists of objects 1 cm (0.39 in) or smaller. The mid-2009 update to
the NASA debris FAQ places the number of large debris items over 10 cm (3.9 in) at
19,000, from one to ten cm at about 500,000 and debris items smaller than 1 cm (0.39 in)
in the tens of millions. Almost all debris weight is concentrated in larger objects; in 2002
about 1,500 objects, each weighing more than 100 kg (220 lb), accounted for over 98
percent of the 1,900 tons of debris then known in low Earth orbit.
Since space debris is generated by man-made objects, the total possible mass of debris is
the total mass of all spacecraft and rocket bodies which have reached orbit. The actual
mass is less, since the orbits of some objects have decayed. The debris mass, dominated by
larger objects (most of which have been detected), has remained relatively constant despite
the addition of many smaller objects. Using a 2008 figure of 8,500 known debris items,
their total mass is estimated at 5,500 t (12,100,000 lb)
Every satellite, space probe and manned mission can potentially leave space debris. Any
impact between two objects of sizable mass can generate spall from the collision. Each
piece of spall can cause further damage, creating more space debris. With a large-enough
collision (between a space station and a defunct satellite, for example), the amount of
debris could make low Earth orbit impossible.
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In LEO there are few "universal orbits" which keep spacecraft in particular rings (in
contrast to GEO, a single widely-used orbit). The closest are the sun-synchronous orbits
that maintain a constant angle between the Sun and the orbital plane. LEO satellites
provide global coverage in many orbital planes, and the 15 orbits per day typical of LEO
satellites result in frequent approaches between objects. Since Sun-synchronous orbits are
polar, the polar regions are common crossing points.
In the presence of space debris, orbital perturbations change the orbital plane's direction
over time and collisions can occur from any direction. Collisions usually occur at high
speed, typically several kilometres per second. Such a collision will normally create large
numbers of objects in the critical size range, as in the 2009 satellite collision. For this
reason, the Kessler syndrome generally applies only to the LEO region; a collision creates
debris crossing other orbits, leading to a cascade effect.
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At the most commonly-used low Earth orbits for manned missions, 400 km (250 mi) and
below, air drag helps keep the zones clear. Collisions below this altitude are less of an
issue, since their fragment orbits have a perigee at (or below) this altitude. The critical
altitude also changes as a result of space weather, which expands and contracts the upper
atmosphere. An expansion of the atmosphere leads to increased drag on the fragments and
a shorter orbit lifetime; during the 1990s, an expanded atmosphere was a factor in reduced
orbital-debris density.[10] Another factor was fewer launches by Russia, who made the vast
majority of launches in the 1970s and 1980s.
At higher altitudes, where atmospheric drag is less significant, orbital decay takes longer.
Slight atmospheric drag, lunar perturbations and solar radiation pressure can gradually
bring debris down to lower altitudes (where it decays), but at very high altitudes this may
take millennia.[12] Although high-altitude orbits are less commonly used than LEO and the
onset of the problem is slower, the numbers progress toward the critical threshold more
quickly.
The problem is especially significant in geostationary orbits (GEO), where satellites
cluster over their primary ground targets and share the same orbital path. Orbital
perturbations are a factor in a GEO, causing longitude drift of the spacecraft and
precession of the orbital plane if uncorrected. Active satellites maintain their position with
thrusters, but inoperable ones (such as Telstar 401) are collision hazards. Close approaches
(within 50 meters) are estimated at one per year.[14] Although velocities in GEO are low
among geostationary objects, when a satellite becomes derelict it assumes a
geosynchronous orbit; its orbital inclination increases about .8° and its speed increases
about 100 miles per hour (160 km/h) per year. Impact velocity peaks at about 1.5 km/s
(0.93 mi/s), and the debris field poses less short-term risk than a LEO collision, but a
satellite would almost certainly be knocked out of operation. Large objects, such as solarpower satellites, are especially vulnerable to collisions.
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