Application of Random Texture in Cholesteric Liquid Crystal for Security Devices

Abstract

We proposed the application of fingerprint textures in cholesteric liquid crystal for a security device that can be used as an index for distinguishing individual artificial materials, for example, ID cards. The randomness of such texture was checked quantitatively by normalized cross-correlation and found to be high. For the fixation of the fingerprint texture a photo-polymerization technique was used, and the fixed pattern was invariable even at high temperature. These results indicate that fingerprint texture in cholesteric liquid crystal realizes the unique and permanent properties of human fingerprints.

Keywords:

• Artificial fingerprint device
• cholesteric liquid crystal
• fingerprint texture
• optical texture
• security device