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Guiding microscale swimmers using teardrop-shaped posts.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Davies Wykes, Megan S  ORCID logo  https://orcid.org/0000-0003-0316-0432
Zhong, Xiao 
Tong, Jiajun 
Adachi, Takuji 
Liu, Yanpeng 

Abstract

The swimming direction of biological or artificial microscale swimmers tends to be randomised over long time-scales by thermal fluctuations. Bacteria use various strategies to bias swimming behaviour and achieve directed motion against a flow, maintain alignment with gravity or travel up a chemical gradient. Herein, we explore a purely geometric means of biasing the motion of artificial nanorod swimmers. These artificial swimmers are bimetallic rods, powered by a chemical fuel, which swim on a substrate printed with teardrop-shaped posts. The artificial swimmers are hydrodynamically attracted to the posts, swimming alongside the post perimeter for long times before leaving. The rods experience a higher rate of departure from the higher curvature end of the teardrop shape, thereby introducing a bias into their motion. This bias increases with swimming speed and can be translated into a macroscopic directional motion over long times by using arrays of teardrop-shaped posts aligned along a single direction. This method provides a protocol for concentrating swimmers, sorting swimmers according to different speeds, and could enable artificial swimmers to transport cargo to desired locations.

Description

Keywords

cond-mat.soft, cond-mat.soft

Journal Title

Soft Matter

Conference Name

Journal ISSN

1744-683X
1744-6848

Volume Title

13

Publisher

Royal Society of Chemistry (RSC)