Inducing Propulsion of Colloidal Dimers by Breaking the Symmetry in Electrohydrodynamic Flow

Fuduo Ma, Xingfu Yang, Hui Zhao, and Ning Wu

Phys. Rev. Lett. 115, 208302 – Published 10 November 2015

Abstract

We show that dielectric colloidal dimers with broken symmetry in geometry, composition, or interfacial charges can all propel in directions that are perpendicular to the applied ac electric field. The asymmetry in particle properties ultimately results in an unbalanced electrohydrodynamic flow on two sides of the particles. Consistent with scaling laws, the propulsion direction, speed, and orientation of dimers can be conveniently tuned by frequency. The new propulsion mechanism revealed here is important for building colloidal motors and studying collective behavior of active matter.

Received 21 July 2015

DOI:https://doi.org/10.1103/PhysRevLett.115.208302

Authors & Affiliations

Fuduo Ma¹, Xingfu Yang¹, Hui Zhao², and Ning Wu^1,*

¹Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, USA
²Department of Mechanical Engineering, University of Nevada, Las Vegas, Nevada 89154, USA