19-06-2012, 02:11 PM
Nanotechnology
Nanotechnology.ppt (Size: 2.69 MB / Downloads: 90)
What Is Nanotechnology?
.Research and technology development aimed to
understand and control matter at dimensions of
approximately 1 - 100 nanometer – the nanoscale ?
.Ability to understand, create, and use structures, devices
and systems that have fundamentally new properties and
functions because of their nanoscale structure ?
.Ability to image, measure, model, and manipulate matter on
the nanoscale to exploit those properties and functions ?
.Ability to integrate those properties and functions into
systems spanning from nano- to macro-scopic scales ?
Tools
Nanotechnology tools include microscopy techniques and equipment that permit visualization and manipulation of items at the nanoscale such as cells, bacteria, and viruses, and to detect single molecules to better understand the nature of science. The range of tools includes the atomic force microscope (AFM), scanning tunneling microscope (STM), molecular modeling software and various production technologies.
Top-down approach
1. The top-down approach is analogous to making a stone statue. You take a bulk piece of material and modify it, by carving or cutting in the case of stone, until you have made the shape you want. The process involves material wastage and is limited by the resolution of the tools you can use, restricting the smallest sizes of the structures made by these techniques. Examples of this kind of approach include the various types of lithographic techniques (such as photo-, ion beam-, electron- or X-ray-lithography) cutting, etching and grinding.
Bottom-up
The second approach is known as the bottom-up approach. This can be thought of as the same approach one would take to build a house: one takes lots of building blocks and puts them together to produce the final bigger structure. There is less wastage with this technique, and strong covalent bonds will hold the constituent parts together.
A good example of this kind of approach is found in nature; all cells use enzymes to produce DNA by taking the component molecules and binding them together to make the final structure. Chemical synthesis, self-assembly, and molecular fabrication are all examples of bottom-up techniques.
Nanotechnology.ppt (Size: 2.69 MB / Downloads: 90)
What Is Nanotechnology?
.Research and technology development aimed to
understand and control matter at dimensions of
approximately 1 - 100 nanometer – the nanoscale ?
.Ability to understand, create, and use structures, devices
and systems that have fundamentally new properties and
functions because of their nanoscale structure ?
.Ability to image, measure, model, and manipulate matter on
the nanoscale to exploit those properties and functions ?
.Ability to integrate those properties and functions into
systems spanning from nano- to macro-scopic scales ?
Tools
Nanotechnology tools include microscopy techniques and equipment that permit visualization and manipulation of items at the nanoscale such as cells, bacteria, and viruses, and to detect single molecules to better understand the nature of science. The range of tools includes the atomic force microscope (AFM), scanning tunneling microscope (STM), molecular modeling software and various production technologies.
Top-down approach
1. The top-down approach is analogous to making a stone statue. You take a bulk piece of material and modify it, by carving or cutting in the case of stone, until you have made the shape you want. The process involves material wastage and is limited by the resolution of the tools you can use, restricting the smallest sizes of the structures made by these techniques. Examples of this kind of approach include the various types of lithographic techniques (such as photo-, ion beam-, electron- or X-ray-lithography) cutting, etching and grinding.
Bottom-up
The second approach is known as the bottom-up approach. This can be thought of as the same approach one would take to build a house: one takes lots of building blocks and puts them together to produce the final bigger structure. There is less wastage with this technique, and strong covalent bonds will hold the constituent parts together.
A good example of this kind of approach is found in nature; all cells use enzymes to produce DNA by taking the component molecules and binding them together to make the final structure. Chemical synthesis, self-assembly, and molecular fabrication are all examples of bottom-up techniques.