SAN FRANCISCO—An international team of researchers reported designing a multi-component molecular motor that can be moved clockwise and counterclockwise, a breakthrough they say could help pave the way for nanoscale devices that can be used for everything from powering quantum computers to sweeping away blood clots in arteries.
The team of scientists, led by Saw Wai Hlam a professor of physics and astronomy at Ohio University, claims its invention is the first stand-alone molecular motor with multiple parts. The results of the group's study were recently published in the journal Nature Nanotechnology.
The scientists demonstrated that they could control the motion of the motor with energy generated by electrons from a scanning tunneling microscope tip. The motor is about 2 nanometers in length and 1 nanometer high, and was constructed on a gold crystal surface, according to the study.
This illustration shows the structure of the molecular motors.
Credit: Saw-Wai Hla
At a temperature of minus 315 degrees Fahrenheit, the motor could move independently through thermal excitation, the researchers reported. When scientists cooled the sample to minus 450 degrees, the motor stopped rotating, they said. The researchers selectively applied electron energy to different parts of the motor to prompt it to move clockwise and counterclockwise.
"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.
The scientific team—which was also led by Christian Joachim of A*Star in Singapore and CEMES/CNRS in France and Gwenael Rapenne of CEMES/CNRS—reported designing a stationary base of atoms that is connected to an upper moving part by one atom of ruthenium, which serves as the molecular motor's "ball bearing." The upper piece of the motor features five arms made of iron atoms. The researchers said 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, according to Hla.
The scientists now plan to use this model to build more complex machines with components that could be automated, Hla said.
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