Importance of the Critical Point in Thermotropic Nematic Liquid Crystals in Terms of Their Sensitivity

The critical point (CP) of liquid crystals has proven to be of immense significance in terms of their sensitivity and their ability to respond to even the slightest external stimuli, such as surface interactions and applied electric or magnetic fields. In this article we focus on the mathematical approach to achieving the the minimal free energy potential of a ther-motropic liquid crystal - which we prove to happen at the CP - via an applied external electric field and surface interactions caused by biomolecules at the interface. We graph-ically present the free energy behavior, which can be simplified to a 4th order polynomial. We also explain how this phenomenon could be used to achieve extremely high sensitivity in liquid crystalline sensors, based on nematic liquid crystal droplets (temperature sensors, biodetectors, light-sensitive sensors). We also give a few plausible causes and mechanisms responsible for heightened sensitivity directly related to the CP in general.