Dong Ki Yoon, featured ILCC liquid crystal artist, September 2009

Polarizing optical microscopic image taken with 40x objective of a confined B7 liquid crystalline phase of a banana molecule in the silicon based channel with 5 μm depth and width. The 30˚ tilted sample shows various colorful ribbon- or filament-like structures and these grow very slowly through the channel as cooling down at a rate of 0.02˚C/min from isotropic phase. This optical pattern can be changed with rotating sample and it shows various periodic morphologies under crossed-polarizers. The image size is approximately 350 x 240 μm.
Jury comment: an unusual liquid crystal texture reflecting the unusual sample geometry. The strong colors and linear geometry make it very attractive.
Dong Ki Yoon is a post-doctoral research associate at the University of Colorado at Boulder working with Prof. Noel A. Clark and Prof. Ivan I. Smalyukh and the Liquid Crystal Materials Research Center (LCMRC) after being an I2CAM Junior Exchange Awardee. His current research interests are focused on the study of the special phenomena and defects of liquid crystals in marginal space and laser induced defects of liquid crystals.
Prior to joining the LCMRC he received his Ph.D. (2007) degree about ‘molecular ordering & orientation of semi-fluorinated supramolecular LCs in external fields’ in Dept. of chemical and biomolecular engineering from KAIST in Korea, and then worked for ‘advanced lithographic nanofabrication project’ in Samsung Electronics Co. for 2 years.