Foiling friction by jiggling a junction.Friction can cause a hard-disk drive to crash or a microscopic motor to seize. One problem is that the lubricants in the minuscule gaps between surfaces of such devices settle into semi-solid layers that resist slipping motions.
A rhythmic resizing of those gaps will break up the layers and keep things gliding easily, according to computational and experimental results presented in the June 25 Journal of Physical Chemistry B The Journal of Physical Chemistry B publishes scientific articles reporting research on the chemistry of materials, including nanostructures, macromolecules, statistical mechanics, and the thermodynamics of condensed matter, biophysical chemistry, as well as the structures and .
"Typically we think of replacing the lubricant," says Uzi Landman of the Georgia Institute of Technology Georgia Institute of Technology, in Atlanta, Ga.; coeducational; state supported; chartered 1885, opened 1888. It is a member school in the university system of Georgia. Significant among its facilities and programs are the Frank H. in Atlanta, who coauthored the computational report. "This is the first [study] that says: Keep the same lubricant and do something external."
Prior studies by Landman and his colleagues found that a waxy waxy (wak´se)
1. composed of or covered by wax.
2. resembling wax, especially denoting some combination of pliability, paleness, and smoothness and luster. lubricant such as hexadecane would separate into four or five stable, motion-resistant layers, but only if the size of the gap filled by the lubricant remained fixed.
In new supercomputer simulations, Landman's team confirmed that if the gap becomes a little smaller or larger, molecules rearrange, disturbing the order and reducing friction. Rapidly varying the spacing by as little as 5 percent of a 2-nanometer, lubricant-filled gap caused "ultralow" friction, the team says.
In an accompanying experimental report, researchers at the Laboratory for Surface Science and Technology in Zurich and at the University of California, Santa Barbara History
The predecessor to UCSB, Santa Barbara State College, focused on teacher training, industrial arts, home economics, and foreign languages. Intense lobbying by an interest group in the City of Santa Barbara led by Thomas Storke and Pearl Chase persuaded the State describe sliding lubricated lu·bri·cate
v. lu·bri·cat·ed, lu·bri·cat·ing, lu·bri·cates
1. To apply a lubricant to.
2. To make slippery or smooth.
To act as a lubricant. surfaces against each other while oscillating the top surface by less than 0.1 nm. Friction dropped markedly, they report--in one circumstance, tailing to less than a tenth of what it was with no oscillations oscillations See Cortical oscillations. .