Fig. 1: Responsiveness of chiral liquid crystals to external electric field frequency stimulation.
From: Dynamically actuated soft heliconical architecture via frequency of electric fields
a A diagrammatic sketch of the previous frequency response of (I) the structural deformation between the transparent planar state and scattering focal conic state of the helicoidal structure and (II) tuning the reflective color of the helicoidal structure through dielectric heating with an obvious thermal effect (over 40 K). The angle between the long axis of the LC molecule and the helical axis is always a right angle. b Schematic illustration of frequency-actuated heliconical soft architecture through delicate coupling among the frequency-dependent thermal effect, field-induced dielectric torque and elastic equilibrium at a relatively low electric field strength. (I) The helicoidal superstructure where LC molecules were perpendicular to the helical axis in the absence of an applied electric field. (II) The heliconical superstructure with an electric field signal across the LC cell of the initial frequency and strength E > Ea, in which the LC molecules twisted around the helical axis with an oblique angle of θ. (II–V) The heliconical pitch length P and oblique angle θ increased with increasing frequency, resulting in wide spectral range tunability of the reflection spectrum. Herein, Ea was the threshold of the transition from the helicoidal helix to the heliconical helix.
