From NineSigma, a Swiss advanced security solutions provider, finds out. PFAS free Low refractive index materials used in printed transparent multilayer foil structures for optical devices.

Nine Sigma’s client is open to any PFAS-free material/polymer or coating approach that can be scaled up in the short term.


Nine Sigma’s client, a Swiss advanced security solutions provider, is developing a new process for optical devices with a low refractive index (LRI) layer consisting of a multilayer foil structure. The difference in refractive index between the layers prevents light from escaping the structure.

Fluoropolymers are commonly used for low refractive index applications due to low polarizability and optical transparency at desired thicknesses. Because of these properties, Nine Sigma’s client currently uses a perfluorinated polymer, namely a perfluoropolyether (PFPE)-urethane dimethacrylate (specific refractive index of 1.33). This polymer is used in UV-curable formulations that are applied in the roll-to-roll process during foil production.

With this project, NineSigma’s client aims to identify and test PFAS-free low refractive index polymers/coatings/materials that may be printable on other polymer surfaces.

Submissions for this challenge must be received by March 15, 2024.

Source: Nine sites