A presentation on NanotechnologyIntroduction"Nano" comes from the Greek "dwarf". It is used in the metric system torefer to "billionth" - a nanometre (nm) is a billionth of a metre, Putanother way, this is about 1/50,000th the width of a human hair. Normaloffice paper is about 100,000nm thick.Nanotechnologists will typically work in the range 1-100nm. Some facts to visualize Nano A nm is about the width of six bonded carbon atoms your fingernails grow approximately one nanometer per second. Another way to visualize a nanometer: 1 inch = 25,400,000 nanometers A red blood cell is ~7,000 nm in diameter, and ~2000 nm in height A virus is ~100 nm
Nanotechnology Nanotechnology is the ability to make things using techniques and tools that are being developed today to place every atom and molecule in a desired place. Nanotechnology is often referred to as a general-purpose technology. That’s because in its mature form it will have significant impact on almost all industries and all areas of society. It offers better built, longer lasting, cleaner, safer, and smarter products for the home, for communications, for medicine, for transportation, for agriculture, and for industry in general.Nanotechnology is the engineering of functional systems at themolecular scale, practically.
Four generations of nanotechnology Progress of technology In active nanostructures are introduced for multitaskingfor example: Actuators, drug delivery devices, and sensors. Around 2010 nanosystems with thousands of interacting components will come up. A few years after that, the first integrated nanosystems, functioning much like a mammalian cell (human cell) with hierarchical systems within systems, are expected to be developed.
Injecting Nanobots in specific areas of body and curing diseases easily Nanomaterials This includes subfields which develop or study materials having unique properties arising from their nanoscale dimensions. Interface and Colloid Science has given rise to many materials which may be useful in nanotechnology, such as carbon nanotubes and other fullerenes, and various nano particles and nano rods. Progress has been made in using these materials for medical applications.
Sculptured thin film Quantum dot Devices used in Nanotechnology Microscopes and other devices Atomic force microscope Scanning tunneling microscope Transmission electron microscope
Atomic force microscopeScanning tunneling microscope
Transmission electron microscope Approaches to the technology Top down approach Bottom down approach Top-down approaches These seek to create smaller devices by using larger ones to direct their assembly. Many technologies descended from conventional solid-state silicon methods for fabricating microprocessors are now capable of creating features smaller than 100 nm, falling under the definition of nanotechnology. Atomic force microscope tips can be used as a nanoscale "write head" to deposit a chemical upon a surface in a desired pattern in a process called dip pen nanolithography. This fits into the larger subfield of nanolithography.
Design of a Silicon Nanowire using top down approach Bottom-up approaches These seek to arrange smaller components into more complex assemblies. DNA nanotechnology utilizes the specificity of Watson-Crick basepairing to construct well-defined structures out of DNA and other nucleic acids. Approaches from the field of "classical" chemical synthesis also aim at designing molecules with well-defined shape (e.g. bis- peptides).Construction of a molecular device using bottom up approach
Subfields Bio nanotechnology DNA nanotechnology Nano Molecular self-assembly Nano biotechnology Nano engineering Nano medicine Nano Synthetic molecular motors
Some of Current researches This device transfers energy from nano-thin layers of quantum wells to nanocrystals above them, causing the nanocrystals to emit visible light. Graphical representation of a rotaxane, useful as a molecular switch.
Some practical applicationsSame feelNanotech should not be confused with miniaturisation – although it willlead to smaller components in chips
Nature knowsThe gecko can walk up glass and even hang upside down.The hairs (spatulae) on its feet are so small they can exploit forces thatpull molecules together, sticking the gecko to the ceiling.Nanotech can make sticky tape lined with gecko-like synthetic hairs thatdo the same job.
Little bitsThe cosmetics industry already puts nano-particles in lotions, creams andshampoos.Nano-sized zinc oxide particles are used in suncreams.The particles are particularly good at absorbing ultra-violet rays, butmake the lotion transparent and smooth instead of sticky and white.
Easy cleanPilkington coats the surface of its Activ glass with titanium oxide nano-particles.Sunshine on these special windows triggers a chemical reaction which breaksdown dirt.When water hits the glass, it spreads evenly over the surface, instead offorming droplets, and runs off rapidly taking the dirt with it.
Tuning tubesCarbon nanotubes are sheets of graphite (carbon) that are rolled up onthemselves.Just a few nanometres across, these ultra-strong cylinders can makecomposite coatings for car bumpers that better hold their shape in acrash.The tubes can also absorb hydrogen, which should enable more efficientstorage of future fuels.
No spotsThe clothing industry uses nanotech to make stain-repellent fabrics.A chemical process during manufacture forces liquids to bead up whenspilled on a garment for easy wiping away.Socks that are made with nano-silver particles give anti-microbialprotection, preventing bacteria and fungus that cause itchiness andsmells.
Image of reconstruction on a clean Au(100) surface, as visualizedusing scanning tunneling microscopy. The individual atomscomposing the surface are visible.
Big futureNanotechnology concerns materials and working devices that areengineered at the scale of atoms and molecules.Advances in nanotech will affect electronics and computing,medicine, cosmetics, foods, the military, energy – all walks of life.By 2020, $1 trillion worth of products could be nano-engineered insome way.
Conclusion Nanotechnology is predicted to be developed by 2020 but much depends on our commitment to its research. Like the first human landing on the moon, or the development of the modern computer, the development of molecular manufacturing will require the coordinated efforts of many people for many years. How long will it take? A lot depends on when we start. Presented by , Rm.Gopinathan