Patterned Thin Films for Applications in Security Documents

该项目的目的是开发新的策略来制造设备，使未经授权的复制或伪造更加困难。随着公共复制技术（例如彩色打印机和复印机）的质量迅速提高，伪造钞票和身份证件的问题日益严重。为了打击这一领域的有组织犯罪，需要新的方法来制造安全文件。该项目与世界上最大的安全打印机和纸张制造商De La芸香合作，目的是开发用于安全文件的新设备。基于Steiner教授实验室现有的技术，将开发出表面图案，当照明或观察角度改变时，这些图案将显示出明亮的彩色效果。这种效应是由白色光在具有微米尺寸电介质图案的表面上的干涉引起的。为了实现这一目标，计划了多种策略的组合，包括使用荧光纳米颗粒、多层结构、横向光栅等，全部通过旋涂或软平版印刷方法沉积。

The purpose of this project is the development of novel strategies to manufacture devices that render the unauthorised duplication or falsification more difficult. With the rapidly increasing quality of publicly available replication technology (e.g. colour printers and photo-copying machines), the counterfeit of bank notes and identity documents is becoming and increasing problem. To counteract this field of organised crime, new approaches to manufacture security documents are necessary.In a collaboration with the world's largest security printer and paper maker, De La Rue, the objective of this project is to develop novel devices for security documents. Based on techniques that are available in Prof. Steiner's laboratories, surface patterns will be developed that show a brilliant coloured effect that change when the angle of illumination or observation is changed. This effect arises from the interference of white light on a surface with a micrometre-sized dielectric pattern. To achieve this a combination of strategies are planned, including the use of fluorescent nanoparticles, multilayer structures, lateral gratings, etc., all deposited by spin-coating, or soft lithographic methods.