Excitable Patterns in Active Nematics

L. Giomi, L. Mahadevan, B. Chakraborty, and M. F. Hagan

Phys. Rev. Lett. 106, 218101 – Published 25 May 2011

Abstract

We analyze a model of mutually propelled filaments suspended in a two-dimensional solvent. The system undergoes a mean-field isotropic-nematic transition for large enough filament concentrations, and the nematic order parameter is allowed to vary in space and time. We show that the interplay between nonuniform nematic order, activity, and flow results in spatially modulated relaxation oscillations, similar to those seen in excitable media. In this regime the dynamics consists of nearly stationary periods separated by “bursts” of activity in which the system is elastically distorted and solvent is pumped throughout. At even higher activity, the dynamics becomes chaotic.

Received 16 November 2010

DOI:https://doi.org/10.1103/PhysRevLett.106.218101

Authors & Affiliations

L. Giomi^1,2, L. Mahadevan¹, B. Chakraborty², and M. F. Hagan²

¹School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
²Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02454, USA