Unclonable human-invisible machine vision markers leveraging the omnidirectional chiral Bragg diffraction of cholesteric spherical reflectors
English
Agha, Hakam[University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS) >]
Geng, Yong[University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS) >]
Ma, Xu[University of Luxembourg > Faculty of Science, Technology and Medecine (FSTM) > >]
Avsar, Deniz Isinsu[University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS) >]
Kizhakidathazhath, Rijeesh[University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS) >]
Zhang, Yansong[University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS) >]
Tourani, Ali[University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > Automation >]
Bavle, Hriday[University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > Automation >]
Sanchez Lopez, Jose Luis[University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > Automation >]
Voos, Holger[University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > Automation >]
[en] The seemingly simple step of molding a cholesteric liquid crystal into spherical shape, yielding a Cholesteric Spherical Reflector (CSR), has profound optical consequences that open a range of opportunities for potentially transformative technologies. The chiral Bragg diffraction resulting from the helical self-assembly of cholesterics becomes omnidirectional in CSRs. This turns them into selective retroreflectors that are exceptionally easy to distinguish— regardless of background—by simple and low-cost machine vision, while at the same time they can be made largely imperceptible to human vision. This allows them to be distributed in human-populated environments, laid out in the form of QR-code-like markers that help robots and Augmented Reality (AR) devices to operate reliably, and to identify items in their surroundings. At the scale of individual CSRs, unpredictable features within each marker turn them into Physical Unclonable Functions (PUFs), of great value for secure authentication. Via the machines reading them, CSR markers can thus act as trustworthy yet unobtrusive links between the physical world (buildings, vehicles, packaging,...) and its digital twin computer representation. This opens opportunities to address pressing challenges in logistics and supply chain management, recycling and the circular economy, sustainable construction of the built environment, and many other fields of individual, societal and commercial importance.
Fonds National de la Recherche - FnR ; Office of Naval Research Global - ONRG ; Institute of Advanced Studies, University of Luxembourg ; European Commission - EC
[University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Physics and Materials Science (DPHYMS) >]
