Active colloidal propulsion over a crystalline surface
We study both experimentally and theoretically the dynamics of chemically self-propelled Janus colloids moving atop a two-dimensional crystalline surface. The surface is a hexagonally close-packed monolayer of colloidal particles of the same size as the mobile one. The dynamics of the self-propelled...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2017-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/aa9b4b |
| _version_ | 1797750718812127232 |
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| author | Udit Choudhury Arthur V Straube Peer Fischer John G Gibbs Felix Höfling |
| author_facet | Udit Choudhury Arthur V Straube Peer Fischer John G Gibbs Felix Höfling |
| author_sort | Udit Choudhury |
| collection | DOAJ |
| description | We study both experimentally and theoretically the dynamics of chemically self-propelled Janus colloids moving atop a two-dimensional crystalline surface. The surface is a hexagonally close-packed monolayer of colloidal particles of the same size as the mobile one. The dynamics of the self-propelled colloid reflects the competition between hindered diffusion due to the periodic surface and enhanced diffusion due to active motion. Which contribution dominates depends on the propulsion strength, which can be systematically tuned by changing the concentration of a chemical fuel. The mean-square displacements (MSDs) obtained from the experiment exhibit enhanced diffusion at long lag times. Our experimental data are consistent with a Langevin model for the effectively two-dimensional translational motion of an active Brownian particle in a periodic potential, combining the confining effects of gravity and the crystalline surface with the free rotational diffusion of the colloid. Approximate analytical predictions are made for the MSD describing the crossover from free Brownian motion at short times to active diffusion at long times. The results are in semi-quantitative agreement with numerical results of a refined Langevin model that treats translational and rotational degrees of freedom on the same footing. |
| first_indexed | 2024-03-12T16:37:56Z |
| format | Article |
| id | doaj.art-dede3b07f63d401cbb172f9817bd40a5 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:37:56Z |
| publishDate | 2017-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-dede3b07f63d401cbb172f9817bd40a52023-08-08T14:49:16ZengIOP PublishingNew Journal of Physics1367-26302017-01-01191212501010.1088/1367-2630/aa9b4bActive colloidal propulsion over a crystalline surfaceUdit Choudhury0Arthur V Straube1Peer Fischer2John G Gibbs3Felix Höfling4Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569, Stuttgart, Germany; University of Groningen , Nijenborgh 4, 9747 AG Groningen, The NetherlandsFreie Universität Berlin, Department of Mathematics and Computer Science, Arnimallee 6, 14195, Berlin, GermanyMax Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569, Stuttgart, Germany; Institute for Physical Chemistry, University of Stuttgart , Pfaffenwaldring 55, 70569, Stuttgart, GermanyMax Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569, Stuttgart, Germany; Department of Physics and Astronomy, Northern Arizona University , Flagstaff, AZ 86011, United States of AmericaMax Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569, Stuttgart, Germany; Freie Universität Berlin, Department of Mathematics and Computer Science, Arnimallee 6, 14195, Berlin, Germany; Institute for Theoretical Physics IV, University of Stuttgart , Pfaffenwaldring 57, 70569, Stuttgart, GermanyWe study both experimentally and theoretically the dynamics of chemically self-propelled Janus colloids moving atop a two-dimensional crystalline surface. The surface is a hexagonally close-packed monolayer of colloidal particles of the same size as the mobile one. The dynamics of the self-propelled colloid reflects the competition between hindered diffusion due to the periodic surface and enhanced diffusion due to active motion. Which contribution dominates depends on the propulsion strength, which can be systematically tuned by changing the concentration of a chemical fuel. The mean-square displacements (MSDs) obtained from the experiment exhibit enhanced diffusion at long lag times. Our experimental data are consistent with a Langevin model for the effectively two-dimensional translational motion of an active Brownian particle in a periodic potential, combining the confining effects of gravity and the crystalline surface with the free rotational diffusion of the colloid. Approximate analytical predictions are made for the MSD describing the crossover from free Brownian motion at short times to active diffusion at long times. The results are in semi-quantitative agreement with numerical results of a refined Langevin model that treats translational and rotational degrees of freedom on the same footing.https://doi.org/10.1088/1367-2630/aa9b4bcolloidal microswimmersactive Brownian particleshexagonal close-packed monolayersurface diffusion |
| spellingShingle | Udit Choudhury Arthur V Straube Peer Fischer John G Gibbs Felix Höfling Active colloidal propulsion over a crystalline surface New Journal of Physics colloidal microswimmers active Brownian particles hexagonal close-packed monolayer surface diffusion |
| title | Active colloidal propulsion over a crystalline surface |
| title_full | Active colloidal propulsion over a crystalline surface |
| title_fullStr | Active colloidal propulsion over a crystalline surface |
| title_full_unstemmed | Active colloidal propulsion over a crystalline surface |
| title_short | Active colloidal propulsion over a crystalline surface |
| title_sort | active colloidal propulsion over a crystalline surface |
| topic | colloidal microswimmers active Brownian particles hexagonal close-packed monolayer surface diffusion |
| url | https://doi.org/10.1088/1367-2630/aa9b4b |
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