Abstract
An enticing feature of active materials is the possibility of controlling macroscale rheological properties through the activity of the microscopic constituents. Using a unique combination of microscopy and rheology we study three dimensional microtubule-based active materials whose autonomous flows are powered by a continually rearranging connected network. We quantify the relationship between the microscopic dynamics and the bulk mechanical properties of these nonequilibrium networks. Experiments reveal a surprising nonmonotonic viscosity that strongly depends on the relative magnitude of the rate of internally generated activity and the externally applied shear. A simple two-state mechanical model that accounts for both the solidlike and yielded fluidlike elements of the network accurately describes the rheological measurements.
- Received 28 July 2020
- Accepted 14 September 2020
DOI:https://doi.org/10.1103/PhysRevLett.125.178003
© 2020 American Physical Society
Physics Subject Headings (PhySH)
synopsis
Viscosity of Active Microtubules Uncovered
Published 22 October 2020
Experiments show how to tune the viscosity of “active” filaments found in cells, something that could help in the design of biomimetic materials.
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