Creating Nanostructured Liquid Crystals:
A Directed Bottom-Up Approach

Hiroshi Yokoyama

Nanotechnology Research Institute
National Institute of Advanced Industrial Science and Technology
1-1-4 Umezono, Tsukuba, Ibaraki 305-8568, Japan

Nanostructured Liquid Crystal Project, ERATO
Japan Science and Technology Corporation
5-9-9 Tokodai, Tsukuba, Ibaraki 300-2635, Japan

Deliberate introduction of nanostructures in otherwise homogeneous liquid crystals can potentially be a powerful approach to create naturally nonexistent phases, structures and functions. Owing to the microscopic molecular orientational order and the associated long range curvature elasticity, indigenous liquid crystal structures interact strongly with extrinsic objects on the nanometer scale.
Our rapidly evolving ability to create, manipulate and characterize nanometer scale objects, i.e. Nanotechnology, is opening up a new field of liquid crystal science and technology by allowing us to realize, in part at least, the above scenario. Since it consists in a mesoscale combination of the self-organizing character of liquid crystalline states and the nanostructure design based on the top-down engineering, I refer to it as a ｳdirected bottom-up approachｲ, emphasizing the role of human directive intervention put into the self-organization of a materials system.
In this talk, I present the results of our recent efforts along the directed bottom-up approach as applied to artificial two- and three-dimensional nanostructuring of liquid crystals, particularly those realized by use of a scanning probe technology. For the 2D nanostructuring, for example, we employed the atomic force microscope to nanofabricate frustrated orientational patterns on an aligning surface. By properly designing the symmetry and the degree of frustration, we succeeded in realizing a multistable liquid crystal alignment, which has never been realized by other means, despite its apparent technical utility.