Chennai: Scientists at IIT Madras used an electric current to turn a single, screw-shaped molecule — and found that its rotation enables more current flow through it. The finding could help researchers design electronic switches as small as a molecule.
Helicene has a spiral shape, like a tiny screw, said Anil Kumar Singh , an assistant professor of physics at IIT Madras, who was part of the international study published in the scientific journal Nature. The work, however, remains a laboratory demonstration, not a device ready for everyday use, scientists said. “This is a fundamental proof-of-principle demonstration, rather than a technology ready for practical use,” Singh said.
The researchers placed a molecule called helicene between two gold electrodes, the contacts through which electricity enters and leaves a circuit. To hold the molecule, the team used a method called a mechanically controllable break junction. They opened a tiny gap between gold contacts and suspended the molecule across it so they could adjust the gap with precision. The study draws on an old mechanical idea: the Archimedean screw. Traditionally used to lift water, the device can also work in reverse, allowing flowing water to drive its rotation. The researchers explored a related link between flow and motion, but with electric charge and a single molecule.