Enhanced security through dye-doped cholesteric liquid crystal shells for anti-counterfeiting

We explored the application of fluorescent dye doped Cholesteric Liquid Crystal (CLC) shells for anti-counterfeiting measures. These shells exhibit unique optical properties and, when infused with a fluorescent dye, produce a distinct fluorescent color upon exposure to UV light. We developed a microfluidic device using glass capillaries to generate uniform CLC shells. The shells were analyzed using a Polarizing Optical Microscope (POM) to study their defect structures. For anti-counterfeiting, QR code was encoded with CLC shells that were photopolymerized under ultraviolet light for enhanced durability. In daylight, the code reflects red and blue colors, but under UV light, it reveals the fluorescent dye color. This QR code can only be decrypted with UV illumination in both red and blue CLC shells. The color changes are easily visible to the naked eye, making this technique suitable for immediate verification. By utilizing this straightforward technique, security and chromic-based applications can be implemented with significantly increased cost-effectiveness and efficiency, surpassing the results of traditional approaches. •We built a microfluidic system employing glass capillaries to create monodispersed CLC shells.•Doping CLC shells with fluorescent dye enhances their applicability in security.•Encrypted QR codes reflect red and blue in daytime and release fluorescent dye under UV radiation, providing a dual-mode verification technique.•QR codes can only be decrypted under UV light, adding security to anti-counterfeiting methods.•CLC-based techniques are simpler, cost-effective, and efficient compared to traditional methods.