  We show that micron-scale two-dimensional (2D) honeycomb microwells can
significantly improve the stability of blue phase liquid crystals (BPLCs).
Polymeric microwells made by direct laser writing improve various features of
the blue phase (BP) including a dramatic extension of stable temperature range
and a large increase both in reflectivity and thermal stability of the
reflective peak wavelength. These results are mainly attributed to the
omni-directional anchoring of the isotropically oriented BP molecules at the
polymer walls of the hexagonal microwells and at the top and bottom substrates.
This leads to an omni-directional stabilization of the entire BPLC system. This
study not only provides a novel insight into the mechanism for the BP formation
in the 2D microwell but also points to an improved route to stabilize BP using
2D microwell arrays.
