Fluid Biaxial Banana Smectics: Symmetry at Work 

Perhaps one of the most surprising results in the past 10 years was the prediction of Brand et al. [1] that fluid biaxial smectics made from comopunds without asymmetric carbons could, by symmetry, have a spontaneous polarization, P, in the layer plane. They called this construct, which can be either ferroelectric or antiferroelectric, smectic C₉. Advances gained from their prediction include the development of highly efficient electrets for broad-band telecommunications [2, 3] as well as a basic non-linear model [4] for TLAFs, thresholdless antiferroelectrics [5], now seen in beatiful, CMOS compatible, active matrix liquid crystal displays [6] (figure 1).