Advanced Functional Materials, Vol.15, No.2, 217-222, 2005
Enhanced electro-optic behavior for shaped polymer cholesteric liquid-crystal flakes made using soft lithography
Polymer cholesteric liquid-crystal (PCLC) flakes were investigated for their electro-optical behavior under an applied alternating-current field. Shaped flakes, fabricated using soft lithography and suspended in dielectric-fluid-filled cells, reoriented more uniformly than randomly shaped flakes made by fracturing of PCLC films. Extensive characterization found shaped flakes to be smooth and uniform in size, shape, and thickness. Reorientation in applied fields as low as tens of mV(rms) mum(-1) was fastest for flakes with lateral aspect ratios greater than 1:1, confirming theoretical predictions based on Maxwell-Wagner polarization. Brilliant reflective colors and inherent polarization make shaped PCLC flakes of interest for particle displays.