Figure 1
The rotational behavior of LCDs on microcomb electrodes. (a) Top view schematic illustration of the model device. We defined x- and y-axes as shown in this figure. (b) Cross-sectional view (α–α′) of the model device. We patterned comb-Au/Cr electrodes on the lower glass substrate and dispersed LCDs just above the electrodes. The thickness of the cell was 10 µm. (c) POM images of an LCD. We defined the angle between the x-axis and the striped texture as θ. (d) Schematic illustration showing the dielectric anisotropy of LCD. Dielectric constants parallel and perpendicular to the striped texture and denoted as ε|| and ε⟂, respectively. The LC sample has positive dielectric anisotropy (Δε = ε||− ε⟂ > 0). (e) POM images of LCD on microcomb electrodes before voltage application, and white arrows indicate the direction of n. POM images of LCDs after voltage application with θ∞ = (f) 0°, (g) − 45°, and (h) − 90°. Snapshots were taken every 2/3 s. We represent n(t) and initial n(t = 0) as red arrows and white dashed arrows, respectively. (i) POM image of LCDs after voltage (20 V, 10 kHz) application for 5 s, and white arrows indicate n. We divide the observation area into three zones surrounded by red, green, and blue lines depending on the equilibrium direction of LCDs. (j) Time evolution of θ. Red, green, and blue markers indicate the θ(t) of LCD at the corresponding area of (i). (k) Voltage distribution on the microcomb electrodes calculated numerically by COMSOL. The color map indicates the electric potential. We showed the direction of electric fields as arrows.
