Indian-Led Study Shows Electricity Can Spin Molecules Faster
An Indian-led international research effort has found that electricity can set a single molecule spinning in a controlled way, dramatically increasing the current that flows through it. The study indicates that the flow of current could be amplified by up to 100 times, a finding that may influence the design of future miniature electronics.
The research brought together scientists from India, Israel, Germany, Denmark and China. Dr. Anil Kumar Singh and his colleagues at IIT Madras took part in the work, which has been published in the journal Nature. The announcement was made on 23 October.
Researchers caution that the results are still at an early stage. They say more studies are necessary before such technology can become part of routine devices.
The molecule at the centre of the study is called helicene, which has a coiled, screw-shaped design. The scientists placed it between two minute gold electrodes and applied an electric potential. This made it possible to observe how the molecule moved and how current traveled through it.
The measurements revealed that once electricity was applied, the molecule passed through several states before settling into a repeating rotational pattern. As it turned, it entered configurations that allowed electrons to pass more freely. The result was a rise of roughly 100 times in the current moving across the molecule.
IIT Madras highlighted a particularly important observation: the team could also control which way the molecule rotated. Among the 122 cases where the direction of change could be clearly determined, all followed an identical cycle. Whenever the electrical polarity was switched, the rotation sequence was reversed.
The experiment drew on an idea inspired by the Archimedes screw, a device historically used to move water from lower to higher ground. The scientists asked whether a similar relationship might be established between electricity and rotational motion within a molecule.
The work has deepened scientific understanding of how electricity, molecular movement and the transfer of motion are linked at the atomic scale. Going forward, this knowledge could help in building small electronic switches and components whose current flow is governed by molecular motion.
The team next intends to investigate whether circularly polarised light or unusual types of electric current could likewise guide molecular motion. Such possibilities could open fresh avenues for managing molecules through light and the rotation of electrons.