Assessing stiffness of nanofibres in bacterial cellulose hydrogels: Numerical-experimental framework

This work presents a numerical-experimental framework for assessment of stiffness of nanofibres in a fibrous hydrogel - bacterial cellulose (BC) hydrogel - based on a combination of in-aqua mechanical testing, microstructural analysis and finite-element (FE) modelling. Fibrous hydrogels attracted growing interest as potential replacements to some tissues. To assess their applicability, a comprehensive understanding of their mechanical response under relevant conditions is desirable; a lack of such knowledge is mainly due to changes at microscale caused by deformation that are hard to evaluate in-situ because of the dimensions of nanofibres and aqueous environment. So, discontinuous FE simulations could provide a feasible solution; thus, properties of nanofibres could be characterised with a good accuracy. An alternative - direct tests with commercial testing systems - is cumbersome at best. Hence, in this work, a numerical-experimental framework with advantages of convenience and relative easiness in implementation is suggested to determine the stiffness of BC nanofibres. The obtained magnitudes of 53.7-64.9GPa were assessed by calibrating modelling results with the original experimental data.