Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > News > Flow into very small holes

July 9th, 2007

Flow into very small holes

Abstract:
In the late 1910s and early 1920s a pair of scientists independently developed an equation that describes how a fluid rises in a capillary tube as a function of time. The formula—the Lucas-Washburn equation—was based on observable macroscopic properties such as surface tension, viscosity, and radius of the capillary tube. It predicted that the height a fluid rose to in a given amount of time to be proportional to the square root of that time. For example: if in one second a fluid rose one millimeter, then it would take four seconds for it to rise two millimeters. The work behind this equation depended on the materials having defined macroscopic properties. As science has moved into the realm of the very small, where materials may no longer be continuous, but discrete; many of the equations that hold true at large scales fail at these new small scales. This is often why nanotechnology has attracted so much attention, new properties that can be exploited by working on such small scales.

Recently, a real scientific controversy has been brewing over this relationship and whether it still holds true at very small length scales. Some groups have reported that the height a fluid scales rises proportionally slower than the time, and other say that the height rises in a linear fashion with time. While this may not seem like a big deal to many, it is to the applications that rely on capillary action to function. Capillary action is at the heart of many technologies, such as dry-wicking fabrics, adsorbent paper towels, or newer nano-scale lab-on-a-chip devices that are poised to revolutionize many areas of science. Without an accurate understanding of how fluids move at these small scales, these technologies face even larger hurdles than they already do. Laboratory experiments on nanoscale capillary action have proven inconclusive to date. To probe this phenomenon in much greater detail, a team of researchers from Germany and Bulgaria developed a computer simulation to study how fluids move into very small tubes.

Source:
arstechnica.com

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Discoveries

Raman Whispering Gallery Detects Nanoparticles September 1st, 2014

A new, tunable device for spintronics: An international team of scientists including physicist Jairo Sinova from the University of Mainz realises a tunable spin-charge converter made of GaAs August 29th, 2014

Nanoscale assembly line August 29th, 2014

Copper shines as flexible conductor August 29th, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

Raman Whispering Gallery Detects Nanoparticles September 1st, 2014

A new, tunable device for spintronics: An international team of scientists including physicist Jairo Sinova from the University of Mainz realises a tunable spin-charge converter made of GaAs August 29th, 2014

Nanoscale assembly line August 29th, 2014

New analytical technology reveals 'nanomechanical' surface traits August 29th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE