Related Experiment Video
Updated: Jun 14, 2026

A Micropatterning Assay for Measuring Cell Chirality
Published on: March 11, 2022
Patterning-induced surface chirality and modulation of director twist in a nematic cell
Yoonseuk Choi1, Timothy Atherton, Sameh Ferjani
1Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079, USA. yxc227@case.edu
Abstract:
A substrate coated with a polyimide alignment layer is scribed bidirectionally with the stylus of an atomic force microscope to create an easy axis for liquid-crystal orientation. The resulting noncentrosymmetric topography breaks two-dimensional inversion symmetry and results in a spatial amplitude modulation of an imposed twisted nematic state. This is observed optically as spatially periodic light and dark stripes. When the alignment layer is scribed unidirectionally the centrosymmetric topography maintains inversion symmetry, and no stripes are observed. The appearance of the twist modulation is consistent with a chiral term in the free energy.
Related Concept Videos
Chirality in Nature
Prochirality
Chirality
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Oriented Surfaces
Stereoisomerism of Cyclic Compounds

