Macroscopic LC Ribbon
We put the cell between two crossed polarizers and took the picture by smartphone. It shows a macroscopic LC ribbon. The LC material, we used here is a mixture of dimer LC/nematic LC doped with chiral dopant and it is filled into a cell made by two clean glasses (without surface treatment). We heated the cell to isotropic phase and then put it into the refrigerator, where the temperature was around 10℃. The LC phase is the twist-bend chiral nematic phase. Small circular patterns with four black brushes can be seen in the beginning, and then they turn to layer structures with beautiful colors—the color shifts to a short wavelength at a higher temperature.