Driven Electrolytes Are Agile and Active at the Nanoscale

 This concept has recently also been used to engineer synthetic motors and molecular sensors on the nanoscale or to explain biological processes in nanopores. In this context, the role of the background medium which is the solvent and the resulting hydrodynamic fluctuations play an important role. Particles in such a system are influenced by these stochastic fluctuations, which effectively control their movements.

“When we imagine the environment inside a driven electrolyte at the nanoscale, we might think of a calm viscous medium in which ions move due to the electric field and slowly diffuse around. This new study reveals that this picture is wrong: the environment resembles a turbulent sea, which is highly nontrivial given the small scale,” explains Ramin Golestanian, who is director of the Department of Living Matter Physics at MPI-DS, and author of the study. The study uncovers how the movement of the ions creates large-scale fluctuating fluid currents that stir up the environment and lead to fast motion of all the particles that are immersed in the environment, even if they are not charged. “Interestingly, the behavior exhibits different regimes depending on the time scale and dimensionality of the system,” comments Golestanian. “This analysis highlights the dominant role of many-body hydrodynamic interactions in creating emergent properties in microscopic non-equilibrium systems,” he concludes.

This model helps to describe and predict the behavior or particles at the nanoscale in biophysical systems such as ion channels and nanopores. Likewise, it can be beneficial for the development of nanoscale sensing technologies that detect single molecules.

Read the original article on Max Planck Institute for Dynamics and Self-Organization.