Scientists create coordinated molecular motors for future nanomachines

05/11/2016 - 16:20

Image: Saw-Wai Hla

An international team of scientists has created molecular motors that can communicate and synchronize their movements.

The team, led by physicist Saw-Wai Hla of Ohio University, published an Advanced Online Publication today in the journal Nature Nanotechnology demonstrating that scientists can control the coordinated motions of tiny machines at the nanoscale. The research has implications for the future development of technologies that can be used in computers, photonics and electronics as well as novel nanoscale devices.


Ref: Simultaneous and coordinated rotational switching of all molecular rotors in a network. Nature Nanotechnology (9 May 2016) | DOI: 10.1038/nnano.2016.69


A range of artificial molecular systems has been created that can exhibit controlled linear and rotational motion. In the further development of such systems, a key step is the addition of communication between molecules in a network. Here, we show that a two-dimensional array of dipolar molecular rotors can undergo simultaneous rotational switching when applying an electric field from the tip of a scanning tunnelling microscope. Several hundred rotors made from porphyrin-based double-decker complexes can be simultaneously rotated when in a hexagonal rotor network on a Cu(111) surface by applying biases above 1 V at 80 K. The phenomenon is observed only in a hexagonal rotor network due to the degeneracy of the ground-state dipole rotational energy barrier of the system. Defects are essential to increase electric torque on the rotor network and to stabilize the switched rotor domains. At low biases and low initial rotator angles, slight reorientations of individual rotors can occur, resulting in the rotator arms pointing in different directions. Analysis reveals that the rotator arm directions are not random, but are coordinated to minimize energy via crosstalk among the rotors through dipolar interactions.