Apparent phototaxis enabled by Brownian motion

Niese, Lukas; Wang, Linlin; Das, Sayan; Simmchen, Juliane

doi:10.1039/d0sm01603a

Cited by 17 publications

(17 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Like other photochemical TiO 2 -based micromotors, the gathered TiO 2 micromotors can be powered by photocataltically decomposing surrounding H 2 O 2 fuels. [44][45][46][47][48][49][50] Under a sidewise UV irradiation, the gathered TiO 2 micromotors perform negative phototaxis as a flock (TiO 2 -MF) in the medium with the H 2 O 2 fuel, 43,44 and thus can also be driven to approach and load a large cargo on the fly. The on-the-fly cargo loading is illustrated in Fig.…”

Section: Resultsmentioning

confidence: 99%

Cooperative transport by flocking phototactic micromotors

Zhang

Mou

et al. 2021

Nanoscale Adv.

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Cooperative transport by flocking phototactic micromotors

Zhang

Mou

et al. 2021

Nanoscale Adv.

View full text Add to dashboard Cite

show abstract

“…This ability of microorganisms to recognise changes in the environment and optimize their movement direction towards favorable areas drastically influences their survival rate [1,2] . Tactic behaviour in living systems can be triggered by various physicochemical changes, for instance chemical (chemotaxis) [3] , light (phototaxis) [4,5] , and temperature (thermotaxis) [6] . Microorganisms in aquatic and terrestrial habitats undoubtedly experience another interesting environmental cue, which is the presence of water currents.…”

Section: Introductionmentioning

confidence: 99%

Upstream rheotaxis of catalytic Janus spheres

Sharan¹,

Xiao

Mancuso

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Fluid flow is ubiquitous in many environments that form habitats for microorganisms. The tendency of organisms to navigate towards or away from flow is termed rheotaxis. Therefore, it is not surprising that both biological and artificial microswimmers show responses to flows that are determined by the interplay of chemical and physical factors. In particular, to deepen understanding of how different systems respond to flows, it is crucial to comprehend the influence played by swimming pattern. In recent studies, pusher-type Janus particles exhibited cross-stream migration in externally applied flows. Earlier, theoretical studies predicted a positive rheotactic response for puller-type spherical Janus micromotors. To compare to a different swimmer, we introduce Cu@SiO2 micromotors that swim towards their catalytic cap. Based on experimental observations, and supported by flow field calculations using a model for self-electrophoresis, we hypothesize that they behave effectively as a puller-type system. We investigate the effect of externally imposed flow on these spherically symmetrical Cu@SiO2 active Janus colloids, and we indeedobserve a steady upstream directional response. Through a simple squirmer model for a puller, we recover the major experimental observations. Additionally, the model predicts a unique “jumping” behaviour for puller-type micro- motors at high flow speeds. Performing additional experiments at high flow speeds, we capture this phenomenon, in which the particles “roll” with their swimming axes aligned to the shear plane, in addition to being dragged down- stream by the fluid flow.

show abstract

“…Depending on the microswimmer type, they can be attracted or repelled by chemicals (chemotaxis), a change in flow resistance (rheotaxis) or light (phototaxis). [40,98] In some cases, the microswimmers themselves create a local chemical gradient and respond to it (autochemotaxis). [39] Externally established gradients are difficult to create and maintain but have been proposed to guide particles' paths.…”

Section: Gradients To Guide Artificial Microswimmersmentioning

confidence: 99%