Through-thickness stress relaxation in bacterial cellulose hydrogel
journal contributionposted on 04.02.2016, 11:52 by Xing Gao, Piotr Kusmierczyk, Zhijun Shi, Changqing LiuChangqing Liu, Guang Yang, Igor Sevostianov, Vadim SilberschmidtVadim Silberschmidt
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.
The partial support from the following grants is gratefully acknowledged: FP7 IRSES project TAMER (Grant no. IRSES-GA- 2013-610547) (XG, PK, IS and VVS); China-European Union Technology Cooperation Programme (Grant no. 1110) (ZS and GY); M6 Project (Grant no. PIRSES-GA-2010-269113) (CL and VVS).
- Mechanical, Electrical and Manufacturing Engineering