)
Nanotechnologies will play a major role in the car industry; but don't
hold your breath to see anything like the Volkswagen Nanospyder
futuristic concept car anytime soon. This entrance to the 2006 Los
Angeles Design challenge was supported by hydrogen fuel cells, solar
power, wheel-mounted electric motors and inflatable organic body panels
combine to form the unusual shape of the two-seater concept.According to
its creators – designers based at the Volkswagen Design Center in Santa
Monica – the Nanospyder would be formed out of a latticework of
billions of tiny programmable nano devices measuring less than half a
millimeter in diameter. Each of these tiny devices can be programmed to
be as strong or weak as required meaning active crumple zones can be
created. Clothing the nano-lattice are panels formed out of a mix of
organic materials some of which can inflate to provide further
cushioning in the result of an impact. The material doubles as a power
source as polysynthesis generates small amounts of electricity. This
coupled with hydrogen fuels generates power to drive the tiny electric
motors mounted within the hubs of all four wheels.
OK,
back to today. The automotive sector is a major consumer of material
technologies – and nanotechnologies promise to improve the performance
of existing technologies significantly. Applications range from already
existing – paint quality, fuel cells, batteries, wear-resistant tires,
lighter but stronger materials, ultra-thin anti-glare layers for windows
and mirrors – to the futuristic – energy-harvesting bodywork, fully
self-repairing paint, switchable colors, shape-shifting skin.The basic
trends that nanotechnology enables for the automobile are
lighter but stronger materials (for better fuel consumption and increased safety)
improved engine efficiency and fuel consumption for gasoline-powered cars (catalysts; fuel additives; lubricants)
reduced environmental impact from hydrogen and fuel cell-powered cars
improved and miniaturized electronic systems
better economies (longer service life; lower component failure rate; smart materials for self-repair)
Applications
of nanotechnologies in automobiles. (Source: Hessian Ministry of
Economy, Transport, Urban and Regional Development)The following
examples are but an overview of a large number of efforts and
applications involving nanotechnologies in the automotive industry:
Chassis and exteriorVehicle
weight reduction is a key part of car manufacturers' strategies to
improve fuel economy. Ford's "Atoms to Engines" team for instance looked
at the structure of cast aluminum alloys at near atomic levels. From
this work, a detailed analysis of the structure/property/process
relationship of the aluminum alloy engine blocks has led to reduced
engine weight and, in turn, increased fuel efficiency.Another area is
the substitution of mineral glass windows by polymers. However, until
recently some key performance specifications had not been reached;
scratch resistance and long term ultraviolet resistance remained
challenges. Recent advances involving nanotechnology are helping
polycarbonate window developers to overcome these
challenges.Nanoengineered thermoplastic materials allow a weight
reduction of up to 40% compared to traditional steel chassis parts.With
regard to paints and surface coatings, nanostructured surfaces result in
improved paint adhesion and color durability. Self-cleaning will become
standard on windscreens and car body shells. Scratch-resistant,
dirt-repellent, UV-resistant and self-healing car paints are
applications that already exist or are in development.
TiresTires
are one of the early applications of nanostructured materials in
automobiles. Carbon black was the first nanomaterial to be used by the
automotive industry in tires as a pigment and reinforcing agent.The key
to tire performance is the mixture of the rubber – but its optimization
requirements can be contradictory (highly complex chemical and physical
interactions between the rubber and the filler material): While the tire
needs good grip its rolling resistance has to be low as well.Some 30%
of the tire cover consists of reinforcing filler which makes possible
wanted properties such as grip, abrasion resistance, resistance to
initial wear and tear, and tear propagation. There are three products
that significantly improve the properties of natural rubber: soot,
silica and organosilane. Now being produced in nanoscale form, these
particles as well as the cross-linking with the natural rubber molecules
play a key role for tire properties.
PropulsionBuilding
an electric car needs to take into account four basic requirements –
powerful and safe energy storage to give the car a sufficient driving
range; engines and associated electronic components that make best use
of the stored onboard energy; light-weight components to compensate for
the (at the moment still) extra weight of the batteries; and all that at
a price that can compete with gasoline-powered automobiles.Lithium ion
batteries are currently being intensively developed worldwide for use in
electric vehicles. The consensus view among researchers is that the
battery will be of the lithium-ion type, but which of the lithium-ion
chemistries to use is still a major question.Nanotechnology holds great
promise for improving the performance and life-times of the Li-ion
batteries. It also has the potential to enhance the energy and power
density, shorten the recharge time, as well as decrease the size and
weight while improving safety and stability of the batteries. A large
number of companies such as Altair Nanotechnologies, mPhase
Technologies, A123 Systems, Li-Tec Battery GmbH, NanoEner Technologies,
Next Alternative Inc., Nexeon Ltd. etc. are actively pursuing the
development of nano-enabled batteries while some others are already
producing them (see here for an overview of major producers/developers
of nano-based batteries and their product range).Nanotechnology is also
key to improving fuel cell performance of future generations of
hydrogen-powered cars.One of the leading fuel cell technologies
developed, in particular for transportation applications, is the proton
exchange membrane (PEM) fuel cell, also known as polymer electrolyte
membrane fuel cells – both resulting in the same acronym PEMFC. These
fuel cells are powered by the electrochemical oxidation reaction of
hydrogen and by the electroreduction of the oxygen contained in
air.Although nanotechnology promises cheap bipolar materials using
nanocomposites, more efficient non-platinum electrocatalysts, and
thermally stable and more durable membranes to become available in the
near future, the precious metal platinum still remains the workhorse of
PEM fuel cells. One way to minimize platinum usage is to increase
catalytic efficiency by nanostructuring the platinum metal; another way
of eliminating the use of platinum altogether is by exploring the use of
much cheaper non-precious metal catalysts where the nanostructured
surfaces match or exceed the catalytic properties of platinum.
Under the hoodFor
fuel cell cars, hydrogen sensors will be a critical component for
safety and widely needed. They will detect leaks long before the gas
becomes an explosive hazard. Researchers have already developed
thin, flexible hydrogen sensors using nanostructured materials, i.e.,
single-walled carbon nanotubes decorated with palladium nanoparticles.Of
course, we will be stuck with gas-guzzling cars for quite some time to
come. Improved fuel efficiency and the reduction of harmful exhaust
emissions are two key areas where nanotechnology applications will make
an impact.In today's automobiles, 10-15 per cent of the fuel consumption
is influenced by engine friction due to the friction loss at the moving
mechanical parts (piston, crank drive, valve drive). Nanocoatings
applied to mechanical parts, and nanostructured lubricants, help reduce
friction and abrasion and thereby improve fuel efficiency.
The
tribological processes at the piston/cylinder wall interfaces take
place at the nanoscale. (Source: Daimler AG Research &
Development)Another example of the many aspects of the above-mentioned
"Atoms to Engines" project by Ford is developing a thermally sprayed
nanocoating that could replace the heavier cast iron liners that provide
the necessary wear resistance of cylinder bores in aluminum block
engines. This thin wear-resistant coating reduces weight and improves
friction performance while delivering equal durability and reliability
to the product.Piezo fuel injection technology is now used not only in
diesel engines, but also in their petrol counterparts. In the case of
direct injection, a pump first builds up high pressure before it shoots
the fuel finely dosed into the combustion chamber of the cylinder via a
nozzle. The precision with which this happens directly influences the
combustion process. The higher the pressure and the more precisely the
dose and time of injection can be controlled, the more efficient fuel
combustion will be. Nanocrystalline piezoelectric materials will improve
these piezoelectric materials.For exhaust cleaning in petrol-powered
cars, systems based on three-way catalysts are used. These can convert
the three main pollutants or pollutant types – carbon monoxide, nitric
oxides and hydrocarbons – as far as possible and thus remove them from
the exhaust gas. During the conversion of toxic to non-toxic gases
nanotechnologies play a crucial role. The impact of catalysts generally
depends on the size of the surface.If the material used for the
catalytic function is scaled to the nanometer range, the specific
surface increases drastically. The composition and structure are chosen
such that exhaust gases interact optimally with the catalytically active
coating, and their chemical transformation into harmless substances is
accelerated.
InteriorCar
interior application will mostly deal with comfort issues –
dirt-repellent and antimicrobial textiles and surfaces, nanoparticulate
air filters, anti-glare coatings of mirrors and instruments. Or how
about climate-controlled car seats based on thermoelectrics – materials
that convert electricity directly into heating or cooling.
Electric systems and electronicsElectronics
is an innovation driver in the automotive sector as more and more
components are being controlled electronically, electromechanically or
electromagnetically. Nanostructured actor components could substitute
current microsystems technology-based direct injection systems for
instance.Spintronics promises to revolutionize computing. While
conventional complementary metal-oxide semiconductors (CMOS), a
technology used today in all types of electronics, rely on electrons'
charge to power devices, the emerging field of spintronics exploits
another aspect of electrons – their spin, which could be manipulated by
electric and magnetic fields. With the use of nanoscaled magnetic
materials, spintronics or electronic devices, when switched off, will
not have a stand-by power dissipation problem. With this advantage,
devices with much lower power consumption, known as non-volatile
electronics, can become a reality.
Spintronics
applications in cars. (Source: Centro Ricerche FIAT)The quickly
emerging hybrid car sector not only uses batteries to store energy for
the electric drive mode, it also pushes recuperation technologies, i.e.
the re-use of braking energy. Here, the moving energy is converted into
electrical current via generator during braking and stored in
accumulators or super or ultra capacitors. Nanotechnologies are expected
to have a major impact in this area. For instance, scientists are
already producing ultra-lightweight, bendable batteries
and supercapacitors in the form of everyday paper.Micro-structured solar
cells can already be integrated into sunroofs and are offered as
options on some cars. Using nanostructured and flexible plastic solar
cells with a thickness of less than 1 micron, it will become possible to
cover larger areas of the car exterior with solar energy harvesting
thin-films.The overall electrical to optical efficiency for lighting
applications in today's cars is only about 1%. This will be considerably
improved by the development of diffractive and microoptics, new light
sources, and their integration with the power supply.
NanoMobilIn
2004, Germany, through its Federal Ministry of Education and Research
(BMBF), established a specific nanotechnology funding program –
NanoMobil –
in connection with automotive technologies and in order to keep the
German car industry and its suppliers competitive. Numerous research
institutes, suppliers and automotive companies have been participating
in several interdisciplinary projects. The following chart shows the
range of topics covered by NanoMobil and gives an indication of the wide
range of nano-applications within the automotive sector:
Funded projects within the lead innovation project NanoMobil.
By Michael Berger. Copyright Nanowerk
Read more: http://www.nanowerk.com/spotlight/spotid=18972.php#ixzz2KySAdCxK
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