title: Through-thickness stress relaxation in bacterial cellulose hydrogel.
abstract: Biological hydrogels, e.g. bacterial cellulose (BC) hydrogel, attracted increasing interest in recent decades since they show a good potential for biomedical engineering as replacements of real tissues thanks mainly to their good biocompatibility and fibrous structure. To select potential candidates for such applications, a comprehensive understanding of their performance under application-relevant conditions is needed. Most hydrogels demonstrate time-dependent behaviour due to the contribution of their liquid phase and reorientation of fibres in a process of their deformation. To quantify such time-dependent behaviour is crucial due to their exposure to complicated loading conditions in body environment. Some hydrogel-based biomaterials with a multi-layered fibrous structure demonstrate a promise as artificial skin and blood vessels. To characterise and model time-dependent behaviour of these multi-layered hydrogels along their through-thickness direction is thereby of vital importance. Hence, a holistic study combining mechanical testing and micro-morphological observations of BC hydrogel with analytical modelling of its relaxation behaviour based on fraction-exponential operators was performed. The results show a good potential to use a fraction-exponential model to describe such behaviour of multi-layered hydrogels, especially at stages of stress decay at low forces and of stress equilibrium at high forces.
authors.affiliation: Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire LE11 3TU, Loughborough, UK.
authors.forename: Xing
authors.initials: X
authors.lastname: Gao
authors.affiliation: Department of Mathematics, Aberystwyth University, Aberystwyth, UK.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kuśmierczyk
authors.affiliation: College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire LE11 3TU, Loughborough, UK.
authors.forename: Changqing
authors.initials: C
authors.lastname: Liu
authors.affiliation: College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Guang
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Mechanical and Aerospace Engineering, New Mexico State University, Las Cruces, USA.
authors.forename: Igor
authors.initials: I
authors.lastname: Sevostianov
authors.affiliation: Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire LE11 3TU, Loughborough, UK. Electronic address: V.Silberschmidt@lboro.ac.uk.
authors.forename: Vadim V
authors.initials: VV
authors.lastname: Silberschmidt
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D008422:Materials Testing; D013314:Stress, Mechanical
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D002482:Cellulose
keywords: Bacterial cellulose hydrogel; Fraction-exponential operators; Rheology; Stress-relaxation test; Time-dependent behaviour