Nano-Motors...Where's the Nano-Boat?

Inspired by the ATP synthase motor in all eukaryotic mitochondria, researchers have long toyed with developing a nano-motor that could convert ion gradients into motion.

The basic premise is exploiting the natural tendency of molecules to diffuse from high to low concentrations, and harnessing this flow of ions at a particular site on a membrane—this can either a biological lipid membrane, or a synthetic carbon nanotube shell. At that site is a nano-rotor sitting in a casing made of stacks of graphene sheets. As the ions pass through the rotor’s casing, it causes a rotational motion in the rotor.

Researchers have experimented on a variety of conditions to test the effects on the motor including the density of ions, amount of ions, applications of electrical fields, temperature, and magnetic fields. Researchers at Shahid Beheshti University in Tehran, have proposed a theoretical nano-carrier that could be utilized to transport various molecules in a charged liquid environment. Carbon nanotubes attached to the main rotor provide lateral thrust. The proposed carrier would only move, however, until the gradient between the carbon membrane disapated.

A. Lohrasebi. 2008. “Computational modeling of an ion-driven nanomotor”. Journal of Molecular Graphics and Modeling.