Probing active nematics with in situ microfabricated elastic inclusions

• 成果类型: Article
• 署名作者: Velez-Ceron, Ignasi; Guillamat, Pau; Sagues, Francesc; Ignes-Mullol, Jordi
• 署名单位: University of Barcelona; University of Barcelona; University of Barcelona; Barcelona Institute of Science & Technology; Institut de Bioenginyeria de Catalunya
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13510
• DOI: 10.1073/pnas.2312494121
• 发表日期: 2024-03-12
• 关键词: topological defects; DYNAMICS; motion

摘要

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, lb and its activity parameter, a. For this, we develop a method that allows us to rapidly photo -polymerize compliant elastic inclusions in the continuously remodeling active system. Moreover, we quantitatively settle longstanding theoretical predictions, such as a postulated relationship encoding the intrinsic time scale of the active nematic in terms of n and a. 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 capabilities, we demonstrate strategies for defect encapsulation, quantification of defect mechanics, and defect interactions, enabled by the versatility of the microfabrication strategy that allows to combine elastic motifs of different shapes and stiffnesses that are fabricated in situ.