High-fidelity spherical cholesteric liquid crystal Bragg reflectors generating unclonable patterns for secure authentication.

ABSTRACT: Monodisperse cholesteric liquid crystal microspheres exhibit spherically symmetric Bragg reflection, generating, via photonic cross communication, dynamically tuneable multi-coloured patterns. These patterns, uniquely defined by the particular sphere arrangement, could render cholesteric microspheres very useful in countless security applications, as tags to identify and authenticate their carriers, mainly physical objects or persons. However, the optical quality of the cholesteric droplets studied so far is unsatisfactory, especially after polymerisation, a step required for obtaining durable samples that can be used for object identification. We show that a transition from droplets to shells solves all key problems, giving rise to sharp patterns and excellent optical quality even after p

SUBMITTER: Geng Y 

PROVIDER: S-EPMC4882534 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature