Flat-twisted-helical transition in composed gel sheets and self assembled chiral molecules

We recently presented a new chirality creating mechanism in elastic strips. in such frustrated bodies, the chiral configuration is determined in a competition between bending and stretching energies, controlled by a dimensionless parameter $\tilde {w}=w\sqrt {k/t} $, in which $w$ is the strip's width, $t$ -- its thickness and $k$ - the spontaneous curvature. I will show the geometrical and mechanical equivalence between such elastic strips and self assembled molecules made of twisted elements. I will also show experiments in responsive gels, showing how a continuous variation in $\tilde {w}$ yields an ordered shape transition from flat to twisted and helical shapes and to tubes. Similar transitions have been observed in self assembled macromolecules.