Near wall void growth leads to disintegration of colloidal bacterial streamer

Ishita Biswas; Ranajay Ghosh; Mohtada Sadrzadeh; Aloke Kumar

doi:10.1016/j.jcis.2018.03.074

Near wall void growth leads to disintegration of colloidal bacterial streamer

J Colloid Interface Sci. 2018 Jul 15:522:249-255. doi: 10.1016/j.jcis.2018.03.074. Epub 2018 Mar 23.

Authors

Ishita Biswas¹, Ranajay Ghosh², Mohtada Sadrzadeh¹, Aloke Kumar³

Affiliations

¹ Department of Mechanical Engineering, University of Alberta, Edmonton T6G 2G8, Canada.
² Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816, USA.
³ Department of Mechanical Engineering, Indian Institute of Science, Bangalore, India. Electronic address: alokekumar@iisc.ac.in.

PMID: 29604443
DOI: 10.1016/j.jcis.2018.03.074

Abstract

We investigated the failure of thick bacterial floc-mediated streamers in a microfluidic device with micropillars. It was found that streamers could fail due to the growth of voids in the biomass that originate near the pillar walls. The quantification of void growth was made possible by the use of 200 nm fluorescent polystyrene beads. The beads get trapped in the extracellular matrix of the streamer biomass and acted as tracers. Void growth time-scales could be characterized into short-time scales and long time-scales and the crack/void propagation showed several instances of fracture-arrest ultimately leading to a catastrophic failure of the entire streamer structure. This mode of fracture stands in strong contrast to necking-type instability observed before in streamers.

Keywords: Bacteria; Failure; Microfluidics; Streamers.

MeSH terms

Biofilms
Biomass
Dimethylpolysiloxanes / chemistry*
Fluorescent Dyes / chemistry
Lab-On-A-Chip Devices
Nanoparticles / chemistry
Polystyrenes / chemistry
Pseudomonas fluorescens / physiology*

Substances

Dimethylpolysiloxanes
Fluorescent Dyes
Polystyrenes
baysilon