  We study avenues to shape multistability and shape-morphing in flexible
crystalline membranes of cylindrical topology, enabled by glide mobility of
dislocations. Using computational modeling, we obtain states of mechanical
equilibrium presenting a wide variety of tubular crystal deformation
geometries, due to an interplay of effective defect interactions with
out-of-tangent-plane deformations that reorient the tube axis. Importantly,
this interplay often stabilizes defect configurations quite distinct from those
predicted for a two-dimensional crystal confined to the surface of a rigid
cylinder. We find that relative and absolute stability of competing states
depend strongly on control parameters such as bending rigidity, applied stress,
and spontaneous curvature. Using stable dislocation pair arrangements as
building blocks, we demonstrate that targeted macroscopic three-dimensional
conformations of thin crystalline tubes can be programmed by imposing certain
sparse patterns of defects. Our findings reveal a broad design space for
controllable and reconfigurable colloidal tube geometries, with potential
relevance also to carbon nanotubes and microtubules.
