Tension-Induced Multistability in Inextensible Helical Ribbons

We study the nonmonotonic force-extension behavior of helical ribbons using a new model for inextensible elastic strips. Unlike previous rod models, our model predicts hysteresis behavior for low-pitch ribbons of arbitrary material properties. Associated with it is a first-order transition between two different helical states as observed in experiments with cholesterol ribbons. Numerical solutions show nonuniform uncoiling with hysteresis also occurring under controlled tension. They furthermore reveal a new uncoiling scenario in which a ribbon of very low pitch shears under tension and successively releases a sequence of almost planar loops. Our results may be relevant for nanoscale devices such as force probes.