  Biomolecular motor proteins that generate forces by consuming chemical energy
obtained from ATP hydrolysis are pivotal for organizing broad cytoskeletal
structures in living cells. The control of such cytoskeletal structures
benefits programmable protein patterning; however, our current knowledge is
limited owing to the underdevelopment of an engineering approach for
controlling pattern formation. Here, we demonstrate the tailoring of assembled
patterns of microtubules (MTs) driven by kinesin motors by designing the
boundary shape in fabricated microwells. We found an MT bundle structure along
the microwell wall and a bridging structure perpendicular to the wall.
Corroborated by the theory of self-propelled rods, we further showed that the
alignment of MTs defined by the boundary shape determined the transition of the
assembled patterns, providing a blueprint to reconstruct bridge structures in
microchannels. Our findings provide a geometric rule to tailor the
self-organization of cytoskeletons and motor proteins for nanotechnological
applications.
