A convenient UV indicator for measuring sunscreen efficacy and preventing skin damage

这个校企合作项目的目标是开发一种动态墨水系统，可以在常用防晒产品下涂抹在皮肤上，并向用户指示防晒霜何时褪色，何时重新涂抹。墨水将基于微囊化的光敏染料分子，当暴露在阳光下的紫外线辐射下，这些染料分子会从无色变成有色。涂在这种油墨上的防晒霜可以阻挡UVB辐射，防止油墨变色。当太阳屏消失时，UVB将到达邮票，激活光致变色染料并变色。重新涂抹防晒霜会阻止激活的光线，邮票将恢复到原来的无色状态。第二代系统不仅将向用户提供关于是否需要重新涂抹太阳屏的视觉反馈，它们还将充当剂量计，提供有关接收到的总辐射量的信息。4D实验室的布兰达团队和这家加拿大当地公司的合作将有助于开发新材料和方法来克服一个重要的健康问题，并提供更好的有效使用防晒霜的指南。

The goal for this university-industry collaborative project is to develop a dynamic ink system that can beapplied to the skin under commonly used sunscreen products and indicate to the user when the sunscreen hasworn off and when to reapply it. The ink will be based on microencapsulated photoresponsive dye moleculesthat will change from colourless to coloured when exposed to the UVB radiation in sunlight. The sunscreenworn on top of this stamped ink will block the UVB radiation and prevent the ink from colouring. When thesunscreen wears off, the UVB will reach the stamp, activate the photochromic dyes and become coloured.Reapplication of the sunscreen will block the activating light and the stamp will return to its originallycolourless state.Second generation systems will not only provide visual feed back to the user about the need to reapply thesunscreen, they will also act as dosimeters, providing information about to the total amount of radiationreceived.The collaboration between the Branda group at 4D LABS and this local Canadian company will help developnew materials and methods to overcome an important health problem and provide better guidelines about usingsunscreen effectively.