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Proceedings Paper

E.coli swims faster in tight microtunnels (Conference Presentation)
Author(s): Gaszton Vizsnyiczai; Filippo Saglimbeni; Giacomo Frangipane; Silvio Bianchi; Claudio Maggi; Roberto Di Leonardo

Paper Abstract

Swimming bacteria exploit viscous drag forces to generate propulsion in low Reynolds number environments. A rotating helical flagellar bundle can propel the cell body at typical speeds of ten body lengths per second. Not surprisingly, this ability to efficiently swim is preserved even in confining micro-environments which constitute their typical habitat. Quantitative studies would require the ability of fabricating complex environments with controlled geometrical properties. Experimental studies so far were limited to large diameter micro capillaries or 2D confinement. In this last case, E.coli has been shown to swim with an unaltered speed even when the gap size is slightly larger than the cell body thickness. The case of tight 1D confinement is however more challenging requiring 3D fabrication capabilities. Using two-photon polymerization we fabricate 3D microstructures that can confine swimming bacteria in quasi 1D geometries. We observe individual E.coli cells swimming through a sequence of micro-tunnels with progressively decreasing diameters. We demonstrate that E.coli motility is preserved also in tight 1D confinement. Moreover we find that there's an optimal channel diameter for which the increase in flagellar thrust due to 1D confinement can even overcome the increased drag on the cell body resulting in swimming speeds that can be up to 15% larger then the bulk speed.

Paper Details

Date Published: 10 November 2016
PDF: 1 pages
Proc. SPIE 9922, Optical Trapping and Optical Micromanipulation XIII, 99221K (10 November 2016); doi: 10.1117/12.2237625
Show Author Affiliations
Gaszton Vizsnyiczai, Sapienza Univ. di Roma (Italy)
Filippo Saglimbeni, Sapienza Univ. di Roma (Italy)
Giacomo Frangipane, Sapienza Univ. di Roma (Italy)
Silvio Bianchi, Sapienza Univ. di Roma (Italy)
Claudio Maggi, Sapienza Univ. di Roma (Italy)
Roberto Di Leonardo, Sapienza Univ. di Roma (Italy)

Published in SPIE Proceedings Vol. 9922:
Optical Trapping and Optical Micromanipulation XIII
Kishan Dholakia; Gabriel C. Spalding, Editor(s)

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