Scientists have created the world’s first working nanoscale electromotor
The international team, involving researchers in the US, the Netherlands and Germany, designed a turbine engineered from DNA. It is powered by hydrodynamic flow inside a nanopore, a nanometre-sized hole in a membrane of solid-state silicon nitride.

The tiny motor could spark research into future applications such as building ‘molecular factories’ for useful chemicals, or medical probes of molecules inside the bloodstream to detect diseases such as cancer.

“Common macroscopic machines become inefficient at the nanoscale,” said study co-author Professor Aleksei Aksimentiev, from the University of Illinois at Urbana-Champaign. “We have to develop new principles and physical mechanisms to realise electromotors at the very, very small scales.”

The experimental work on the tiny motor was conducted by Cees Dekker of the Delft University of Technology in the Netherlands and Hendrik Dietz of the Technical University of Munich.

A specialist in ‘DNA origami’, Dietz’s lab manipulated molecules to make the tiny motor’s turbine, which consisted of 30 double-stranded DNA helices engineered into an axle, and three blades of about 72 base pairs. Decker’s lab work demonstrated that the turbine can rotate by applying an electric field, while Aksimentiev’s lab carried out molecular dynamics simulations on a system of five million atoms, to characterise the physical phenomena of how the motor works.

“This new work is the first nanoscale motor where we can control the rotational speed and direction,” Aksimentiev said. That is achieved by adjusting the electric field across the solid state nanopore membrane, as well as the salt concentrations of the fluid that surrounds the rotor.

“In the future, we might be able to synthetize a molecule using the new nanoscale electromotor, or we can use it too as an element of a bigger molecular factory, where things are moved around. Or we could imagine it as a vehicle for soft propulsion, where synthetic systems can go into a blood stream and probe molecules or cells one at a time,” Aksimentiev said.

The Texas Advanced Computing Center (TACC) awarded Aksimentiev an allocation to use Frontera, the top academic supercomputer in the US.

“We were able to accomplish this because of supercomputers," he said. "Supercomputers are becoming more and more indispensable as the complexity of the systems that we build increases. They’re the computational microscopes, which at ultimate resolutions can see the motion of individual atoms, and how that is coupled to a bigger system.”

The work was published in Nature Nanotechnology.

extracted from IMechE website, read more here

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