Self-Organization of a Mesoscale Bristle into Ordered, Hierarchical Helical Assemblies
Boaz Pokroy,
Sung H. Kang,
L. Mahadevan,
Joanna Aizenberg*
Mesoscale hierarchical helical structures with diverse functions
are abundant in nature. Here we show how spontaneous helicity
can be induced in a synthetic polymeric nanobristle assembling
in an evaporating liquid. We use a simple theoretical model
to characterize the geometry, stiffness, and surface properties
of the pillars that favor the adhesive self-organization of
bundles with pillars wound around each other. The process can
be controlled to yield highly ordered helical clusters with
a unique structural hierarchy that arises from the sequential
assembly of self-similar coiled building blocks over multiple
length scales. We demonstrate their function in the context
of self-assembly into previously unseen structures with uniform,
periodic patterns and controlled handedness and as an efficient
particle-trapping and adhesive system.
* To whom correspondence should be addressed. E-mail: jaiz{at}seas.harvard.edu
