Rajdeep Deb, featured ILCC liquid crystal artist, July 2012

Rajdeep Deb
Dr. Rajdeep Deb’s research interests encompass different aspects of materials science, central to which is an abiding passion for the design and synthesis of all different liquid crystal systems with novel molecular architecture. Dr. Deb has in recent years made major leap towards the design of conducting liquid crystalline molecules for high charge carrier mobility. For his contributions to microscopic imaging he garnered numerous honours. Other than research he is very passionate towards development of open learning environment through ICT to raise the standards of learning and teaching in engineering education.
Prior to his current role in JRE Group of Institutions as an Assistant Professor; Dr. Deb was worked in NIT; Silchar as a Lecturer. He spent some time in LCMRC; University of Colorado at Boulder as a visiting researcher in Prof. Ivan I Smalyukh’s lab. His work there particularly concentrated on the studies of the most spectacular defects and structures in B7 phase (such as spirals, ribbons, checkerboard …) using fluorescence confocal polarizing microscopic (FCPM) imaging technique. He holds his MSc degree from Assam University, Silchar and a PhD touching the areas of synthesis of unusual bent core liquid crystalline system.
B7 phases are known for their polarization splay modulated and layer undulated structure and a widely variegated set of textures formed by them which can be visualized in polarized light microscopy, which in turn suggest that they hardly possess any commonality in their organizational themes. During cooling from the isotropic melt, the B7 texture starts appearing with its own various complex structures. This image shows a spectacular display of focal conic-like domains modulated with stripes and checkerboard patterns. A peculiarity that attracts particular attention is the formation of checkerboard patterns out of the developable domain with a fan-shaped texture having extinction brushes parallel and perpendicular to the polarizer. Good contrast and visible edge definition at the boundaries can be realized. To obtain large domain a slower cooling rate was maintained, the sample was cooled down by 0.1oC steps with annealing pauses of several minutes between steps. The picture was taken on a Nikon LV100 POL polarizing optical microscope with Nikon D300 digital camera.

Jury comment: symphony of liquid crystal accordions