Researchers Develop Molecular Electric Motor That Can Self-Assemble

In a first, researchers from the Technical University of Munich (TUM) have successfully developed a molecular electric motor made of genetic material that can convert electric energy into kinetic energy. The team used the DNA origami method to create the nanomotors which can self-assemble and whose motion can be controlled. With the development of the nanomotor, researchers have tried to replicate the natural molecular motors in our body like ATP synthase that performs different functions. 

The DNA origami method used to assemble the motors from DNA molecules was invented by Paul Rothemund in 2006. The team at TUM further developed this method. “We’ve been advancing this method of fabrication for many years and can now develop very precise and complex objects, such as molecular switches or hollow bodies that can trap viruses. If you put the DNA strands with the right sequences in solution, the objects self-assemble,” said Hendrik Dietz, Professor of Biomolecular Nanotechnology at TUM.

The novel nanomotor consists of three components namely base, platform, and rotor arm. While the base is roughly 40 nanometres high, the rotor arm measures 500 nanometres in length. The base is fixed to the glass plate in solution via chemical bonds on a glass plate. The rotor arm has been mounted on the base to enable rotation.

The third component, the platform, lies between the rotor and the base and helps the motor work as intended. It has obstacles that influence the movement of the rotor arm. The rotor arm has to bend slightly upward to keep rotating while an obstacle is posed.

The rotor arms of the motor tend to move randomly in one direction due to its collision with the molecules from the solvent. When an AC voltage is applied to the motor via two electrodes, the rotor arms can be made to rotate in a targeted and continuous motion.

“The new motor has unprecedented mechanical capabilities: it can achieve torques in the range of 10 piconewton times nanometer. And it can generate more energy per second than what’s released when two ATP molecules are split,” explained Ramin Golestanian, who led the theoretical analysis of the mechanism of the motor.

Researchers hope that the new motor can have technical applications in the future and if developed further, it could help in achieving user-defined chemical reactions in the way ATP synthase makes ATP using rotation.