基于聚合物分散液晶的纳米腔上伪装二维码防伪标签
Anti-counterfeiting tags with camouflaged QR codes on nanocavities, using polymer-dispersed-liquid-crystals
AI总结：
本文提出了一种将激光打印二维码与MIMI纳米腔及聚合物分散液晶相结合的双层级防伪标签，利用液晶热致相变实现二维码的伪装与可读切换，并通过压力测试验证了其长期稳定性和实际集成可行性。
摘要：
伪造问题带来了日益严峻的挑战，推动了对创新且复杂的防伪策略和技术的需求。许多解决方案聚焦于具有光学特征的标签，这些特征对人眼部分或完全伪装，从而阻止造假者。本文中，一个二维码被激光打印在薄塑料箔上，该塑料箔预先涂覆了一种特定的纳米腔，该纳米腔由金属/绝缘体/金属/绝缘体（MIMI）多层结构组成。这种超材料由于其特定设计而在光透射方面具有独特特性。一层薄的聚合物分散液晶，通过在聚合物基体中掺入特定的向列相液晶而制备，能够伪装二维码，使其随后仅在特定热条件下可读。制备了三种防伪标签，每种使用具有各自向列相-各向同性相转变温度的不同液晶。向列相液晶的独特光学性质与光学纳米腔的特殊组合，产生了一种具有两个不同编码层级的新型标签。已进行了包括水浸、弯曲测试和长时间加热在内的压力测试，确保了标签的长期稳定性。所实现的双安全级别防伪标签成本效益高、制造简单，并且由于其柔韧性，可以轻松集成到包装和产品中。
英文摘要：
Counterfeiting poses an evergrowing challenge, driving the need for innovative and sophisticated anti-counterfeiting strategies and technologies. Many solutions focus on tags characterized by optical features that are partially or completely camouflaged to the human eye, thus discouraging scammers. In this paper, a QR code is laser printed on a thin plastic foil previously coated by a specific nanocavity consisting of a metal/insulator/metal/insulator (MIMI) multilayer. This metamaterial possesses unique features in terms of light transmission that are due to the specific design. A thin layer of polymer dispersed liquid crystals, fabricated incorporating specific nematic liquid crystals in a polymer matrix, is able to camouflage the QR code that becomes, then, readable only under specific thermal conditions. Three anti-counterfeiting tags were fabricated, each using a distinct LC with its own nematic-isotropic transition temperature. The peculiar combination of the unique optical properties of nematic liquid crystals and optical nanocavities results in the creation of a novel type of tags showing two different encoding levels. Stress tests including water immersion, bending test, and prolonged heating have been performed ensuring the long-term stability of the tags. The realized two security-level anti-counterfeiting tags are cost-effective, straightforward to manufacture and, thanks to their flexibility, can be easily integrated into packaging and products.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
