WEB Novel strain-stiffening structures: A cell-inspired mechanism
Cells are able to withstand external physical stresses through various mechanisms such as strain-stiffening in which material stiffness increases in response to applied forces. This mechanism is based on the formation of bundled and cross-linked actin stress fibers from intrinsically soft and easily deformable single actin fibers. Here, we developed cell-inspired, synthetic strain-stiffening structures where single actin fibers are mimicked by slats that come into contact with each other upon deformation to resemble the bundling and cross-linking of the fibers and yield an increase in structure stiffness. Besides being completely reversible and independent of deformation speed, the process is attainable in both compression and stretching modes with an ability to attenuate the strain-stiffening effect through changing the structure size and geometry. Detailed finite element modelling and experimental investigation were carried out to study the impact of different geometrical parameters on the strain-stiffening effect of silicone-based structures. As different materials (e.g. biocompatible silicone) were used to fabricate the structures in varying scales, these structures show great potential in flexible electronics and soft robotics systems.