Voltage-controlled formation of short pitch chiral liquid crystal structures based on high-resolution surface topography.

Chiral nematic liquid crystals (CLCs) offer interesting perspectives for device applications and are fascinating materials to study because of their ability to self-assemble into complex structures. This work demonstrates that narrow lines of electron-beam resist on top of an ITO coated glass surface can dramatically influence the formation and growth of short pitch chiral superstructures in the bulk. By applying a voltage to the cell, directional growth of CLC structures along the corrugated surface can be controlled. Below the electric unwinding threshold, chiral structures start to grow along the grating lines with their helical axis parallel to the substrates. This results in a uniform lying helix-like structure at intermediate voltages and a chiral configuration with periodic undulations of the helical axis at low voltages.