Probing active nematics with in-situ microfabricated elastic inclusions

Abstract

In this work, we report a direct measurement of the forces exerted by a tubulin/kinesin active nematic gel as well as its complete rheological characterization, including the quantification of its shear viscosity, η, and its activity parameter, α. For this, we develop a novel method that allows us to rapidly photo-polymerize compliant elastic inclusions in the continuously remodelling active system. Moreover, we quantitatively settle long-standing theoretical predictions, such as a postulated relationship encoding the intrinsic time scale of the active nematic in terms of η and α. In parallel, we infer a value for the nematic elasticity constant, K, by combining our measurements with the theorized scaling of the active length scale. On top of the microrheology capatilities, we demonstrate novel strategies for defect encapsulation, quantification of defect mechanics, and defect interactions, enabled by the versatility of the new microfabrication strategy that allows to combine elastic motifs of different shape and stiffness that are fabricated in-situ and on-time.

Supplementary videos available at: https://tinyurl.com/activeUB

References in corpus (6)

• Spontaneous motion in hierarchically assembled active matter
• Meso-scale turbulence in living fluids
• Topology and Dynamics of Active Nematic Vesicles
• Defect dynamics in active nematics
• Data-driven quantitative modeling of bacterial active nematics
• Probing the shear viscosity of an active nematic

Cited by in corpus (8)

• Asymmetric fluctuations and self-folding of active interfaces
• Chirality, anisotropic viscosity and elastic anisotropy in three-dimensional active nematic turbulence
• Closed-loop control of active nematic flows
• Active nematic pumps
• Spontaneous rotation and propulsion of suspended capsules in active nematics
• Passive defect driven morphogenesis in nematic membranes
• Turbulence to order transitions in activity patterned active nematics
• Defect binding-unbinding transition in active nematic membranes