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

Autor(en)

Yong Geng, JungHyun Noh, Irena Drevensek-Olenik, Romano Rupp, Gabriele Lenzini, Jan P. F. Lagerwall

Abstrakt

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 polymerisation, the polymerised shells sustaining considerable mechanical deformation. Moreover, we demonstrate that, counter to prior expectation, cross communication takes place even between non-identical shells. This opens additional communication channels that add significantly to the complexity and unique character of the generated patterns.

Organisation(en)

Physik Funktioneller Materialien

Externe Organisation(en)

University of Luxembourg, University of Ljubljana, Jožef Stefan Institute (IJS)

Journal

Scientific Reports

Band

6

Anzahl der Seiten

9

ISSN

2045-2322

DOI

https://doi.org/10.1038/srep26840

Publikationsdatum

05-2016

Peer-reviewed

Ja

ÖFOS 2012

103021 Optik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/e7a9595f-2006-4274-a2c8-bfa12316966e