Poroviscoelasticity and compression-softening of agarose hydrogels

Agarose hydrogels are poroviscoelastic materials that exhibit a waterlogged-crosslinked microstructure. Despite an extensive use in biotechnologies and numerous studies of the elastic properties agarose gels, little is known about compressible behavior microstructural changes such fibrillar under compression. The present work investigates mechanical response centimeter-sized pre-molded cylinders when applying compressive strain ramp over extended range loading speed polymer concentration. One original contributions simultaneous monitoring hydrogel volume to determine Poisson’s ratio through spatiotemporal method. linear poroelastic shows at rates less than 0.7 % s?1. critical few percent onset non-linear regime always positive decrease slow ramp. typical deformation mode either dominated by bending semiflexible strands (enthalpic regime) or stretching network (entropic higher Cyclic shear deformations superimposed from 0.5 up 40% further give evidence compression-softening causing transition without dependence upon topology connectivity. Finally, buckling-induced aging weak compression poroviscoelasticity shown impact relaxation normal stress equilibrium stress.