A presentation on NanotechnologyIntroduction "Nano" comes from the Greek "dwarf". It is used in the metric system to refer to "billionth" - a nanometre (nm) is a billionth of a metre, Put another way, this is about 1/50,000th the width of a human hair. Normal office 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 the molecular scale, practically.

Four generations of nanotechnology

Progress of technology

In active nanostructures are introduced for multitasking for 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.

Nanoparticles and Colloids

Colloid Diamondoids Nanocomposite Nanocrystal Nanostructure

Nanocages Nanocomposite Nanofabrics Nanofiber Nanofoam Nanoknot Nanomesh Nanopillar Nanopin film Nanoring Nanorod Nanoshell Nanotube Quantum heterostructure Sculptured thin film

Quantum dot

Devices used in Nanotechnology

Microscopes and other devices

Atomic force microscope Scanning tunneling microscope Transmission electron microscope

Atomic force microscope

Scanning 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 This device transfers energy from nano-thin layers of quantum wells to nanocrystals above them, causing of quantum wells to nanocrystals above them, causing

the nanocrystals to emit visible light.the nanocrystals to emit visible light.

Graphical representation of a rotaxane, Graphical representation of a rotaxane, useful as a molecular switch.useful as a molecular switch.

Some practical applications

Same feel Nanotech should not be confused with miniaturisation – although it will lead to smaller components in chips

Nature knows

The gecko can walk up glass and even hang upside down. The hairs (spatulae) on its feet are so small they can exploit forces that pull molecules together, sticking the gecko to the ceiling.

Nanotech can make sticky tape lined with gecko-like synthetic hairs that do the same job.

Little bits

The cosmetics industry already puts nano-particles in lotions, creams and shampoos. Nano-sized zinc oxide particles are used in suncreams. The particles are particularly good at absorbing ultra-violet rays, but make the lotion transparent and smooth instead of sticky and white.

Easy clean

Pilkington coats the surface of its Activ glass with titanium oxide nano-particles. Sunshine on these special windows triggers a chemical reaction which breaks down dirt. When water hits the glass, it spreads evenly over the surface, instead of forming droplets, and runs off rapidly taking the dirt with it.

Tuning tubesCarbon nanotubes are sheets of graphite (carbon) that are rolled up on themselves. Just a few nanometres across, these ultra-strong cylinders can make composite coatings for car bumpers that better hold their shape in a crash. The tubes can also absorb hydrogen, which should enable more efficient storage of future fuels.

No spots The clothing industry uses nanotech to make stain-repellent fabrics. A chemical process during manufacture forces liquids to bead up when spilled on a garment for easy wiping away. Socks that are made with nano-silver particles give anti-microbial protection, preventing bacteria and fungus that cause itchiness and smells.

Image of reconstruction on a clean Au(100) surface, as visualized using scanning tunneling microscopy. The individual atoms composing the surface are visible.

Big future Nanotechnology concerns materials and working devices that are engineered 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 in some 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