Top-down and bottom-up approaches

There are two types of approaches for synthesis of nano material and fabrication of nano structure.

• top-Down approaches refers to slicing or successive cutting of a bulk material to get nano sized particles.there are two types *attrition ,* milling

• Bottom-up refers to methods where devices 'create themselves' by selfassembly. Chemical synthesis is a good example. Bottom-up should broadly speaking be able to produce devices in parallel and much cheaper than top-down methods, but getting control over the methods is difficult when things become larger and more bulky than what is normally made by chemical synthesis. Of course nature has had time to evolve and optimize self-assembly processes that can do wonders.

Microfabrication made smaller

Much of nanotechnology is based on methods from Microfabrication.

References

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