Security display devices, their production and use
Security documents often incorporate security devices to prevent or hinder counterfeiters. Disclosed herein are security devices that include a fluid or fluids within the devices. Such devices, and security documents that include them, afford new techniques to check whether a security document is a legitimate or counterfeit copy.
1. A security device for a security document, the device comprising a fluidic structure containing a plurality of conduits arranged in a pattern or image and one or more liquids sealed within the plurality of conduits, wherein the fluidic structure is a microfluidic or nanofluidic structure, and
wherein the one or more liquids are sealed within the plurality of conduits so that the plurality of conduits are continuously filled with the one or more liquids;
wherein the one or more liquids filling the plurality of conduits comprise a single liquid phase and wherein each of the plurality of conduits has a dimension of 1 nm to 100 μm between opposing walls.
2. The security device according to claim 1 , wherein the walls comprise one or more materials selected from one of polymers, films, and laminates.
3. The security device according to claim 2 , wherein the walls comprise one or more materials selected from one of thermoplastics, polyolefins, PP, PE, PET, Ultra-Violet curable polymers including free radical systems and cationic systems, Electron-beam curable polymers, BOPP, fluoropolymers, cyclic olefins, thermosetting polymers, spin-on-glass and silicon elastomers, photoresists including two-photon photoresists, and derivates and mixtures thereof.
4. The security document comprising:
a core material; and
at least one security device according to claim 1 present on at least one side of the core material, or at least partially embedded into the core material, such that the device is at least partly visible in reflected light from said at least one side.
5. The security document according to claim 4 , wherein the core material comprises at least one material selected from the group consisting of: paper, polymer, plastic, and combinations or hybrids thereof.