Washington: Scientists have developed the first man-made molecular pump, which transports key proteins that cells need to function, that could be used to power artificial muscles.
The new machine mimics the pumping mechanism of life-sustaining proteins that move small molecules around living cells to metabolise and store energy from food.
For its food, the artificial pump draws power from chemical reactions, driving molecules step-by-step from a low-energy state to a high-energy state - far away from equilibrium.
While nature has had billions of years to perfect its complex molecular machinery, modern science is only beginning to scratch the surface of what might be possible in tomorrow's world, researchers said.
"Our molecular pump is radical chemistry - an ingenious way of transferring energy from molecule to molecule, the way nature does," said Fraser Stoddart from the Northwestern University, the senior author of the study.
"The ring-shaped molecules we work with repel one another under normal circumstances," said Chuyang Cheng, first author of the study.
"The artificial pump is able to syphon off some of the energy that changes hands during a chemical reaction and uses it to push the rings together," Cheng said.
The tiny molecular machine threads the rings around a nanoscopic chain - a sort of axle - and squeezes the rings together, with only a few nanometres separating them.
At present, the artificial molecular pump is able to force only two rings together, but the researchers believe it won't be long before they can extend its operation to tens of rings and store more energy.
Compared to nature's system, the artificial pump is very simple, but it is a start, the researchers say. They have designed a novel system, using kinetic barriers, that allows molecules to flow "uphill" energetically.
Ultimately, they intend to use the energy stored in their pump to power artificial muscles and other molecular machines.
The researchers also hope their design will inspire other chemists working in non-equilibrium chemistry.
The study was published in the journal Nature Nanotechnology.