Chiral Self-Assembly of Flexible High Aspect Ratio Nanopillars

We present experimental self-assembly of high aspect ratio nanopillars into chiral clusters in response to capillary force. We take advantage of pillars with an aspect ratio of up to 500 with adjustable dimension, shape, porosity and two-dimensional arrangement fabricated by two-photon lithography and oxygen plasma etching. Using such freedom of design in combination with the kinetically controlled evaporation of a liquid, we devise systems where we can externally introduce five-fold disclination defects on the surface of clustered pillars due to geometrical frustration. In addition, we can kinetically control the number of assembled clusters per array and adjust the handedness of the twists in asymmetrical arrays of nanopillars.