Electrically and Mechanically Driven Instabilities in Thin Layers of Nematic Liquid Crystal Gel

Friday, October 1, 2004 - 9:30am - 10:20am
Keller 3-180
Robert Meyer (Brandeis University)
A layer of nematic liquid crystal is aligned as a single crystal between rigid plates, and gelled into a soft solid by formation of a crosslinked polymer network within the nematic phase. Changing the temperature produces changes in the nematic order parameter, resulting in stresses in the gel, due to its confinement. Likewise, an applied electric field produces a torque on the nematic director, either stabilizing or destabilising its initial orientation. The combination of elastic and electric stresses leads to buckling instabiltites in the sample, which are observed by polarized light microscopy. Experimental results and theoretical analysis will be presented.