title: Mechanical properties of a mature biofilm from a wastewater system: from microscale to macroscale level.
abstract: A fundamental understanding of biofilm mechanical stability is critical in order to describe detachment and develop biofouling control strategies. It is thus important to characterise the elastic deformation and flow behaviour of the biofilm under different modes of applied force. In this study, the mechanical properties of a mature wastewater biofilm were investigated with methods including macroscale compression and microscale indentation using atomic force microscopy (AFM). The mature biofilm was found to be mechanically isotropic at the macroscale level as its mechanical properties did not depend on the scales and modes of loading. However, the biofilm showed a tendency for mechanical inhomogeneity at the microscale level as indentation progressed deeper into the matrix. Moreover, it was observed that the adhesion force had a significant influence on the elastic properties of the biofilm at the surface, subjected to microscale tensile loading. These results are expected to inform a damage-based model for biofilm detachment.
authors.affiliation: a School of Electrical, Electronic and Mechanical Engineering , University College Dublin (UCD) , Dublin , Ireland.
authors.forename: Ashkan
authors.initials: A
authors.lastname: Safari
authors.affiliation: b Faculty of Mechanical Engineering and Naval Architecture , University of Zagreb , Zagreb , Croatia.
authors.forename: Zeljko
authors.initials: Z
authors.lastname: Tukovic
authors.affiliation: c School of Chemical and Bioprocess Engineering , University College Dublin (UCD) , Dublin , Ireland.
authors.forename: Maik
authors.initials: M
authors.lastname: Walter
authors.affiliation: c School of Chemical and Bioprocess Engineering , University College Dublin (UCD) , Dublin , Ireland.
authors.forename: Eoin
authors.initials: E
authors.lastname: Casey
authors.affiliation: a School of Electrical, Electronic and Mechanical Engineering , University College Dublin (UCD) , Dublin , Ireland.
authors.forename: Alojz
authors.initials: A
authors.lastname: Ivankovic
mesh_terms: D000268:Adhesiveness; D001422:Bacterial Adhesion / Q000502:physiology*; D018441:Biofilms; D057219:Biofouling / Q000517:prevention & control*; D001696:Biomechanical Phenomena; D018625:Microscopy, Atomic Force / Q000379:methods; D014865:Waste Disposal, Fluid / Q000295:instrumentation*; D062065:Wastewater / Q000382:microbiology
chemical_list: D062065:Wastewater
keywords: atomic force spectroscopy; biofilm; elastic modulus; macroscale mechanical testing; viscoelastic properties