Tunable corrugated patterns in an active gel sheet

Abstract

Active matter locally converts chemical energy into mechanical work and, for this reason, it provides new mechanisms of pattern formation. In particular, active gels made of protein motors and filaments are far-from-equilibrium systems that exhibit spontaneous flow,[Kruse2004, Voituriez2005] leading to active turbulence in two and three dimensions[Sanchez2012, Kumar2018] and coherent flow in three dimensions[Wu2017] (3D). Although these dynamic flows reveal a characteristic length scale resulting from the interplay between active forcing and passive restoring forces, the observation of static and long-range spatial patterns in active gels has remained elusive. In this work, we demonstrate that a 2D free-standing nematic active gel, formed spontaneously by depletion forces from a 3D solution of kinesin motors and microtubule filaments, actively buckles out-of-plane into a centimeter-sized periodic corrugated sheet that is stable for several days at low activity. Importantly, the corrugations are formed in the absence of flow and their wavelength and stability are controlled by the motor concentration, in agreement with a hydrodynamic theory. At higher activities these patterns are transient with the gel becoming turbulent at longer times. Our results underline the importance of both passive and active forces in shaping active gels and indicate that a static material can be sculpted through an active mechanism.

References in corpus (12)

• Spontaneous motion in hierarchically assembled active matter
• Meso-scale turbulence in living fluids
• Topology and Dynamics of Active Nematic Vesicles
• Transition from turbulent to coherent flows in confined three-dimensional active fluids
• Self-organized dynamics and the transition to turbulence of confined active nematics
• Tunable structure and dynamics of active liquid crystals
• Spontaneous flow states in active nematics: a unified picture
• Synthesis and materialization of a reaction-diffusion French flag pattern
• Tunable dynamics of microtubule based active isotropic gels
• Defects in nematic membranes can buckle into pseudospheres
• Wrinkling instability in 3D active nematics
• Membrane fluctuations near a plane rigid surface

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• Vesicle shape transformations driven by confined active filaments
• Active cholesterics: odder than odd elasticity
• Wrinkling instability in 3D active nematics
• Wrinkle patterns in active viscoelastic thin sheets
• Fingering Instability of Active Nematic Droplets
• Shear-induced gelation of self-yielding active networks
• A design framework for actively crosslinked filament networks
• Tailoring collective motion of kinesin-driven microtubules via topographic landscapes
• Modeling mechanochemical pattern formation in elastic sheets of biological matter
• Catapulting of topological defects through elasticity bands in active nematics
• Active uniaxially ordered suspensions on disordered substrates
• Front speed and pattern selection of a propagating chemical front in an active fluid
• Shape and size changes of adherent elastic epithelia