Spider silk is a protein material that exhibits extraordinary and nontrivial properties such as the ability to soften and decrease its length by up to ∼60% upon exposure to high humidity. This counter-intuitive process is commonly called supercontraction and is the result of a transition from a highly oriented glassy phase to a disoriented rubbery phase. Our new work presents a model that explains the origins of this phenomena. The insights from this work motivate the development of novel biomimetic materials.
How do we induce twist in tubes without applying a torque?
In nature, such a deformation mode is enabled by material anisotropy. In our new work, we show that isotropic bi-layer tubes with twist incompatible layers can twist upon inflation and extension.
Interestingly, the direction of twist can spontaneously reverse as the load increases, as shown in this video!
Biopolymer networks found in arthropods can experience a significant softening upon swelling! In this work, we model the water-induced softening of resilin, which is a protein network found in arthropods.
Our work suggests that the softening behavior in gels can be controlled by an appropriate design of the network microstructure.
Our new paper titled “Inversion and perversion in twist incompatible isotropic tubes” has been accepted to Extreme Mechanics Letters – congratulations to Nir!
