KAIST researchers have developed a platform technology that arranges symmetric molecules into "microscopic pinwheels," enabling circularly polarized light with a desired rotation direction. The research results were published in the Nature Communications.

Limits of conventional chiral materials

The research team led by Professor Dong Ki Yoon of the Department of Chemistry, in collaboration with researchers from Chungnam National University, Ajou University, Yonsei University and Japan's RIKEN, has developed a technology that spatially confines symmetric nonchiral liquid crystal molecules and applies an electric field to form micrometer-scale chiral pinwheel structures, then permanently replicates them onto polymer nanofibers.

Chirality refers to the property of an object whose mirror image cannot be perfectly superimposed on the original, like a person's left and right hands. Chirality is a key property not only of biological molecules such as proteins and DNA but also of optical materials used in next-generation displays, optical sensors and optical communications.

Until now, producing chiral optical materials has generally required the complex synthesis of molecules with asymmetric structures or the addition of large amounts of chiral substances. This has made fabrication complicated, limited the range of usable materials and made it difficult to realize chiral structures with the same handedness over a large area.