IIT-NITT

Nanotechnology:

The term was first proposed by K. Eric Drexler in the 1970's.

A nanometer is one billionth of a meter It involves the manipulation of the

structure of matter atom-by-atom. It is currently undergoing extensive

development It has not yet yielded significantly

useful commercial product

Definition:

Nonmanufacturing is a term used to describe either the production of nanoscaled materials, which can be powders or fluids, or to describe the manufacturing of parts "bottom up" from nanoscaled materials or "top down" in smallest steps for high precision

Why Nanoscale ?????

High Hardness

More Toughness

No Quantum Forces

The Complete Process:

Nonmanufacturing Vs. Traditional mfg. Bottom -up Products are manufactured one

atomic particle at a time. Top- down Every product begins with a bulk

material processes and is subsequently refined down

Nonmanufacturing Approaches : Top Down and Bottom Up

Self Assembly

Lithography

Electron Beam Induced Deposition

Top Down:

Design begins by specifying complex pieces and then dividing them into successively smaller pieces.

 This approach is deterministic, so it gives control over the process

As smaller and smaller structures are built, it gets exponentially expensive

Problems with the Top-down Process: Cost of new machines and clean

room environments grows exponentially with newer technologies.

Physical limits of photolithography are becoming a problem.

With smaller geometries and conventional materials, heat dissipation is a problem.

Bottom up:

 The individual base elements of the system are first specified in great detail.

 These elements are then linked together to form larger subsystems

This strategy often resembles a "seed" model, whereby the beginnings are small, but eventually grow in complexity and completeness.

Why is Bottom-Up Processing Needed? Allows smaller geometries than

photolithography. Certain structures such as Carbon

Nanotubes and Si nanowires are grown through a bottom-up process.

Is more economical than top-down in that it does not waste material to etching.

Can make formation of films and structures much easier.

Methods Of Bottom Up Approach: Self Assembly : - it’s the natures way techniques . - efficient way than conventional

techniques . Molecular Assembly: - it’s the mans way techniques . - much more emphasis on smaller

and smaller machines

Challenges for the Bottom-Up Approach

Making sure that the structures grow and assemble in the correct way.

Forming complex patterns and structures using self assembly.

Contamination has a significant impact on devices with such small geometries.

Fabricating robust structures.

Lithography:

Electron Beam lithography:

Nano-iprint Lithography :

Focused Ion Beam

Electron Beam lithography:

Nano imprint lithography:

Focused Ion Beam:

Nano manipulation :

The main tools used in nanotechnology are three main microscopes

Transmission Electron Microscope (TEM)

Atomic Force Microscope (AFM)

Scanning Tunneling Microscope (STM)

Other uses of nanotools:

Applications:

Chronometry Devices. Sensor units. Optical devices. Biomedical products. Computing and information storage

devices. Smart materials using nanoscale

devices.

Applications:

Applications:

This chain of microscopic gears can be used to drive micro-engines at speeds of up to 25,000 rpm. Longer chains can also be used in complex applications.

Nano Gear:

THANK YOU