Fingerprint-free surfaces – The Nano Argovia project ReLaFunAF is devoted to functionalizing surfaces with UV-curable coatingsSNI INSight May 2020
A team of researchers from the FHNW School of Engineering, the Paul Scherrer Institute and the company RadLab AG in Killwangen is developing a procedure for functionalizing surfaces with coatings that can repel fingerprints.
At present there are numerous applications that involve treating surfaces with coatings that are cured under UV light. Whereas in the past, curing was achieved primarily by recourse to mercury vapor lamps, these are increasingly being replaced by UV LED lights. However, the use of LEDs often results in the formation of “sticky” layers, as the surface cannot be fully cured. “This phenomenon, which is actually a major problem in other respects, opens up entirely new possibilities for functionalizing surfaces,” explains Dr. Sonja Neuhaus of the FHNW Institute of Polymer Nanotechnology (INKA), who is in charge of the project. “The surface still possesses reactive groups that can be used for covalent binding of functional molecules.”
Functionalization in the second step
In a project backed by the Aargau Research Fund, the team working under Sonja Neuhaus joined forces with RadLab to develop a new process* whereby functional components are applied to the sticky layer in a second coating step, and then fixed in place by means of an additional complete round of UV curing.
In this way, the functional layer does not come into contact with the original substrate. This allows functionalizations that would otherwise adhere to the sample poorly or not at all – a crucial benefit of the chosen method.
Broad range of potential applications
The ReLaFunAF project team will now look into how this principle can be applied to treat surfaces so that they repel even fingerprints.
There is huge demand for surfaces with this kind of protection in the production of decorative items or in the automotive and electronics industries. While various methods leading to fingerprint-resistant properties have already been developed, many of them are unsuited to large-scale applications.
For now, the researchers are using targeted “chemical” structuring to test which combination of properties – for example, lipophilic and hydrophilic – is needed to prevent fingerprints from forming. They will subsequently examine the extent to which the architecture of the network at the nano scale influences this repellent effect.
“Ongoing refinement of coating procedures is crucial to our success. For this Nano Argovia project we have the perfect team with which to successfully hone the ReLaFun process in response to a specific issue.”
Dr. Anna Di Gianni, Technical Director of RadLab AG