Flick a switch, turn a knob or pull a lever and you’re operating an electromechanical device, albeit a complex one. Now an IBEC researcher and his collaborators have broken new ground with a proven concept for the first such electronic component to operate using just a single-molecule electrical contact.
In a study published in Nature Nanotechnology, Ismael Díez Pérez, a researcher in IBEC’s Nanoprobes and Nanoswitches group, and Prof. Nongjian Tao from Arizona State University describe their success in attempting to find a way to simulate the same electromechanical effects achieved on conventional electronics but in a single-molecule device that allows the accurate mechanical control of the current flow.
By studying metal-molecule orbitals coupling, in which a flow of electrons is modulated by the overlapping level of the molecular ‘π-orbitals’ and the orbitals of the electrodes binding to it, they found a new way to control the electrical conductance in a single-molecule junction. “We mechanically modulated the angle of a molecule bridged between two metal electrodes,” explains Ismael. “Changing its angle from highly-tilted to nearly perpendicular to the electrodes changes the conductance by an order of magnitude.”
Single-molecule electromechanical devices would open up huge possibilities in being able to create things at an ever-smaller scale. “We can move things just angstroms of distance with really precise control,” says Ismael. “Being able to reversibly control the current flow with a mechanical perturbation in a single-molecule contact will surely bring new fundamental knowledge on how such contacts operate, and may have an important impact on technological advances in the future.”