文章基本信息

标题：A combined rheometry and imaging study of viscosity reduction in bacterial suspensions
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作者：Vincent A. Martinez ; Eric Clément ; Jochen Arlt 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：5
页码：2326-2331
DOI：10.1073/pnas.1912690117
出版社：The National Academy of Sciences of the United States of America
摘要：Suspending self-propelled “pushers” in a liquid lowers its viscosity. We study how this phenomenon depends on system size in bacterial suspensions using bulk rheometry and particle-tracking rheoimaging. Above the critical bacterial volume fraction needed to decrease the viscosity to zero, ϕ c ≈ 0.75 % , large-scale collective motion emerges in the quiescent state, and the flow becomes nonlinear. We confirm a theoretical prediction that such instability should be suppressed by confinement. Our results also show that a recent application of active liquid-crystal theory to such systems is untenable.
关键词：Escherichia coli ; rheology and imaging ; particle tracking ; particle image velocimetry ; active matter