This molecule walks like a man
Scientists have designed a molecule which, like a human, walks in a straight line on a flat surface, one step at a time. The fact that the motion is fully controllable might lead to applications in molecular computing, for example for storing large amounts of information on nanoscale chips.Scientists have designed a molecule which, like a human, walks in a straight line on a flat surface, one step at a time. This 'nano-walker' -- 9,10-dithioanthracene or DTA -- has two linkers that act as feet. "Obtaining its energy from heat supplied to it, the molecule moves such that only one of the linkers is lifted from the surface; the remaining linker guides the motion of the molecule and keeps it on course." The DTA molecule closely mimics human walking, always having a foot on the surface while the other is pulling the molecule. The fact that the motion is fully controllable might lead to applications in molecular computing, for example for storing large amounts of information on nanoscale chips.
Here is the introduction of this University of California Riverside (UCR) news release.
A research team, led by UC Riverside’s Ludwig Bartels, is the first to design a molecule that can move in a straight line on a flat surface. It achieves this by closely mimicking human walking. The "nano-walker" offers a new approach for storing large amounts of information on a tiny chip and demonstrates that concepts from the world we live in can be duplicated at the nanometer scale – the scale of atoms and molecules.
The molecule – 9,10-dithioanthracene or "DTA" – has two linkers that act as feet. Obtaining its energy from heat supplied to it, the molecule moves such that only one of the linkers is lifted from the surface; the remaining linker guides the motion of the molecule and keeps it on course. Alternating the motions of its two "feet," DTA is able to walk in a straight line without the assistance of nano-rails or nano-grooves for guidance.
Below is an image of the walking molecule (Credit: UCR). This image is one of the 37 frames of this animated version (939 KB).
And here is a link to a short movie of the walking molecule (Quicktime format, 40 seconds, 6.02 MB). This video has been put online -- courtesy of Ludwig Bartels -- by Chemical & Engineering News in "Molecules Take A Walk" (September 27, 2005).
This is fascinating to watch, but will it be useful?
Bartels explained that, ordinarily, molecules move in every unpredictable direction when supplied with thermal energy. "DTA only moves along one line, however, and retains this property even if pushed or pulled aside with a fine probe." Bartels said. "This offers an easy realization of a concept for molecular computing proposed by IBM in the 1990s, in which every number is encoded by the position of molecules along a line similar to an abacus, but about 10 million times smaller."
You'll find additional details by visiting the home pages of Ludwig Bartels and of his group at UCR.
And this research work will be published in an upcoming issue of Physical Review Letters. The current tentative title is "Walking Molecules can Stay the Course."
Finally, for a last piece on information, you can read a previous story about another Bartel's project, "Snapshots of Molecules in Movement."
Sources: UCR News, September 26, 2005; and various web sites
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