Unclonable human-invisible machine vision markers leveraging the omnidirectional chiral Bragg diffraction of cholesteric spherical reflectors  

作　　者：Hakam Agha Yong Geng Xu Ma Deniz IsInsu Avsar Rijeesh Kizhakidathazhath Yan-Song Zhang Ali Tourani Hriday Bavle Jose-Luis Sanchez-Lopez Holger Voos Mathew Schwartzo Jan P.F.Lagerwall 

机构地区：[1]University of Luxembourg,Department of Physics&Materials Science,1511 Luxembourg,Luxembourg [2]University of Luxembourg,Interdisciplinary Centre for Security,Reliability and Trust(SnT),1855 Luxembourg,Luxembourg [3]University of Luxembourg,University of Luxembourg,Department of Engineering,L-1359 Luxembourg,Luxembourg [4]New Jersey Institute of Technology,College of Architecture and Design,University Heights,Newark,NJ,USA

出　　处：《Light(Science & Applications)》2022年第11期2583-2601,共19页光（科学与应用)（英文版）

基　　金：the Luxembourg National Research Fund(FNR),grant reference C20_MS_14771094(ECLIPSE);For the purpose of open access,the author has applied a Creative Commons Atribution 4.0 International(CC BY 4.0)license to any Author Accepted Manuscript version arising from this submission.Further financial support is gratefully acknowledged from the Office of Naval Research Global(Project LAB'RINTH);the Institute of Advanced Studies of the University of Luxembourg(project TRANSCEND);the European Research Council(ERC,Proof-of-C oncept project VALIDATE,Grant Code 862315).

摘　　要：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.

关 键 词：SPHERICAL STERIC CHIRAL 

分 类 号：O62[理学—有机化学]