September 5, 2011
Researchers Develop Motor One Nanometer Wide
Researchers have developed an electric motor that is just a billionth of a meter across.The motor could be used in nanotechnology and in medicine, where tiny devices are used for efficient tasks.
The tiny rotors are based on single molecules and is the first that can be individually driven by an electric current.
The device is now the world's smallest electric motor at 1 nanometer across, shattering the old record of 200 nanometers across. A single strand of human hair is 60,000 nanometers wide.
"There has been significant progress in the construction of molecular motors powered by light and by chemical reactions, but this is the first time that electrically-driven molecular motors have been demonstrated, despite a few theoretical proposals," E. Charles H. Sykes, Ph.D., associate professor of chemistry at Tufts University and senior author on the paper, said in a press release.
"We have been able to show that you can provide electricity to a single molecule and get it to do something that is not just random."
The butyl sulphide molecule was placed on a clean copper surface, where its single sulphur atom acted as a pivot.
The team used the metal tip on the microscope to provide an electrical charge to the motor.
The motor spins in both directions at a rate of 120 revolutions per second. The motor spins at a much faster rate in higher temperatures.
The researchers said breakthroughs would need to be made in the temperatures at which the electric motors operate before it could be used in practical applications.
"Once we have a better grasp on the temperatures necessary to make these motors function, there could be real-world application in some sensing and medical devices which involve tiny pipes. Friction of the fluid against the pipe walls increases at these small scales, and covering the wall with motors could help drive fluids along," Sykes said in a press release.
"Coupling molecular motion with electrical signals could also create miniature gears in nanoscale electrical circuits; these gears could be used in miniature delay lines, which are used in devices like cell phones."
The researchers was published in the September 4 edition of Nature Nanotechnology.
Image 2: “The excitement is in the demonstration that you can provide electricity to a single molecule and get it to do something that´s not just random,” says Charles Sykes. Photo: Alonso Nichols
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