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Sticky and fast

Page history last edited by frogheart@... 11 years, 7 months ago

The rules change when objects are viewed at the nanoscale. Such an object, say an atom, moves constantly and tends to stick to other atoms.

 

The movement is a phenomenon known as Brownian motion and if you were able to see at the nanoscale the pencil or drinking glass that you're holding, everything would be jiggling. That's right. Everything all around you is jiggling all the time. As scientists work with smaller and smaller objects, they experience the impact that Brownian motion has on their attempts to create new materials.[1][2]

 

Due to the electromagnetic forces of adhesion (two examples are the Casimir effect and van der Waals forces), nanoscale objects tend to stick to each other when they come in close contact or collide, which given the amount of movement is inevitable. If you were swimming in a drop of water, it would seem more like swimming in glue. Yet again, the properties at the nanoscale are entirely different.[3]

 

Not all atoms or molecules are equally attractive to each other so some stick together better than others. Factor in the constant motion and collisions and the atoms and molecules that aren't particularly attractive to each other will slide off and move on to collide with other possibly more attractive atoms and/or molecules.

 

There are two basic approaches to developing new materials that exploit nanoscale properties. The top-down approach means that you start at the macroscale (i.e. objects that you and I can touch) making them successively smaller and smaller, shrinking downward until the nanoscale is reached. The other approach, bottom-up, means starting at the nanoscale (with the atoms and molecules) and exploiting the properties specific at that scale, building upward. No matter which approach is chosen, you will always have to solve the engineering issues raised by Brownian motion and stickiness to establish engineering control. (In June 2008, scientists at the HP Labs announced that they had established a 'nano' level of control with memristors. For more about achieving control, under Jump points, click on Memristors.)

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Jump back

The Science behind Nanotech

 

Jump points

Memristors

See me, feel me

Footnotes

  1. Jones, R. A. L. (2007) Soft Machines; Nanotechnology and Life. (originally published 2004, paperback edition 2007) Oxford and New York, Oxford University Press.
  2. Edwards, S. A. (2006) The Nanotech Pioneers; Where Are They Taking Us? Weinheim, Federal Republic of Germany, WILEY-VCH.
  3. Jones, R. A. L. (2007) Soft Machines; Nanotechnology and Life. (originally published 2004, paperback edition 2007) Oxford and New York, Oxford University Press.

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