Scientists design, control movements of molecular motor

Jan 10, 2013
This illustration shows the structure of the molecular motors designed by the international team of scientists. Credit: Saw-Wai Hla

(Phys.org)—An international team of scientists has taken the next step in creating nanoscale machines by designing a multi-component molecular motor that can be moved clockwise and counterclockwise.

Although researchers can rotate or switch individual molecules on and off, the new study is the first to create a stand-alone molecular motor that has multiple parts, said Saw-Wai Hla, an Ohio University professor of physics and astronomy who led the study with Christian Joachim of A*Star in Singapore and CEMES/CNRS in France and Gwenael Rapenne of CEMES/CNRS.

It's an essential step in creating —quantum machines that operate on different than classical machines—that scientists envision could be used for everything from powering quantum computers to sweeping away blood clots in arteries.

In the study, published in Nature Nanotechnology, the scientists demonstrated that they could control the motion of the motor with energy generated by electrons from a tip. The motor is about 2 nanometers in length and 1 nanometer high and was constructed on a gold .

At a temperature of minus 315 degrees Fahrenheit, the motor could move independently through thermal excitation. When scientists cooled the sample to minus 450 degrees, the motor stopped rotating. The researchers selectively applied electron energy to different parts of the motor to prompt it to move clockwise and counterclockwise.

These images, taken with a scanning tunneling microscope, show the molecular motor as it rotates at minus 315 degrees Fahrenheit (top), and stepwise rotations by tunneling electrons at minus 450 degrees (a - h) (bottom image sequence). Credit: Saw-Wai Hla

"If we want to build an actual device based on this motor, we would install electrodes on the surface to create an energy source," Hla said. To construct the molecular motor, the scientific team designed a stationary base of atoms that is connected to an upper moving part by one atom of ruthenium, which serves as the "ball bearing." The upper piece of the motor features five arms made of . The researchers made one arm shorter than the others to be able to track the motion of the machine. The entire device is held upright by using sulfur as an "atomic glue" to secure the motor to the gold surface, Hla explained.

The scientists now plan to use this model to build more complex machines with components that could be automated, Hla said.

Explore further: Special microscope captures defects in nanotubes

Related Stories

Turning an axel mounted molecular wheel

Jan 23, 2007

Researchers at the Centre for Material Development and Structural Studies in Toulouse (CEMES-CNRS) and their colleagues at the Free University of Berlin have, for the first time, managed to control the rotation of a wheel ...

Could a quantum motor do work?

Jul 07, 2009

(PhysOrg.com) -- Ever since the idea of a quantum world was discovered, physicists have been trying their best to create applications and uses that mirror the accomplishments of the classical world. However, due to the fact ...

Workings of molecular motor revealed

Oct 24, 2011

(Medical Xpress) -- The structure and function of a ‘molecular motor’ critical to the functioning of human organs and, when malfunctioning, implicated in cancer, kidney failure, and osteoporosis, ...

Low speed wind tunnel gets new motor

May 28, 2012

A new motor has been installed in the Oran W. Nicks Low Speed Wind Tunnel, replacing a 900RPM, 1,000-horsepower synchronous motor from Allis-Chalmers that was surplused by the U.S. Navy back in World War II.

Scientists discover world's smallest superconductor

Mar 29, 2010

Scientists have discovered the world's smallest superconductor, a sheet of four pairs of molecules less than one nanometer wide. The Ohio University-led study, published Sunday as an advance online publication ...

Recommended for you

Researchers develop world's thinnest electric generator

Oct 15, 2014

Researchers from Columbia Engineering and the Georgia Institute of Technology report today that they have made the first experimental observation of piezoelectricity and the piezotronic effect in an atomically ...

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

kevinrtrs
1 / 5 (5) Jan 10, 2013
OK, now that people are beginning to realize just how difficult it is to built and control things at such a small scale, it is time for evolutionists to meet reality.
ATP synthase is an essential component for most of life bearing organisms. Withtout it the organism would have no energy to perform ANY other process. ATP synthase also just happens to be the most efficient motor known. PLUS, it is driven not by electrons but by protons.
There is just no way for this astonishing nanoscale machine to have been assembled by purely random physical processes. The vibrational, torsional and chemical problems at that scale are just too great - exactly as the current designers have found out to their chagrin. ASk them why it is that they have to experiment at such low temperatures, then compare that to ATP synthase.
Have fun trying to explain the existence of this miraculous machine that exists by the billions at body temperature.
RealScience
4.7 / 5 (3) Jan 11, 2013
@kevin - mutation may be random, but natural selection is not random (and even mutation is no longer random because life has evolved to retain more mutations in less critical areas than in life-critical areas). So the evolution of ATP synthase (yes, enzymes and other proteins 'evolve' through mutations in their DNA templates) was driven by non-random selection as well as quasi-random mutation.

I see that you are still preaching non-science on a science web site. That is disrespectful! Your religion is none of my business, but if scientists don't preach science on your religious web sites, please return the favor and keep your non-science of off our site.

And I see that you are still using a computer, a device based on discoveries made by the same science methods that support evolution. That's hypocritical!

Most religious people are fine, as are most scientists.
So who died and made you a disrespectful hypocrite?
_Stargazer_one
5 / 5 (2) Jan 15, 2013
@kevin - Please note that you are using an old Creationist canard called the Argument from Incredulity which is basically a negative argument. There may or may not be a natural explanation at this moment for the existence of ATP synthase, but that is very much the case for many phenomena unexplained in the past which now can be answered with natural science. The eye, for example, was considered too complex for evolution to explain, but vision is now known to have quite an evolutionary past.

This type of god-of-the-gaps argument used by ID creationists needs to be sent to the dustbin in a hurry.
jacky 750
5 / 5 (2) Jan 15, 2013
OK, now that people are beginning to realize just how difficult it is to built and control things at such a small scale, it is time for evolutionists to meet reality.


So if it's difficult to build means it's designed? Then who designed it? If you claim something is designed you must provide evidence for the designer & the mechanism he used, as a bare minimum. Otherwise it's just a belief, not science. Simply saying "it's complex or it looks like a man-made machine, so it's designed" is nonsense. That's what the "intelligent design" advocates foolishly do.

Do you know that the catalysis in ribosomes is carried out by RNA? This RNA is a 'ribozyme' and it's hypothesized that such ribozymes were the first genetic material to evolve, since RNA can both store genetic information $ perform catalysis. So one could imagine the very first ribosomes as nothing but RNA. It could have slowly associated with other proteins over several 100 million yrs to produce the current ribosome.
jacky 750
5 / 5 (2) Jan 15, 2013
@kevin,

Here are scientific hypotheses for the evolution of ATP synthases:

http ://www .sciencedirect.com/science/article/pii/S0014579304010841
http ://www .life.illinois.edu/crofts/bioph354/Evol_F1.html

No "intelligent intervention" required.