Fraunhofer IMWS scientists have developed a new nanoparticle-based coating that prevents fingerprint smudges from affecting stainless steel and metal surfaces.
Greasy fingerprints on shiny stainless steel surfaces are not only unattractive, they are also known to attack the surface in question.
Take for instance surfaces covered in dark fingerprints; they sometimes require arduous chemical polishing which erodes the quality of the original coating.
Now IMWS scientists along with their counteraprts at FEW Chemicals GmbH have found a way to say goodbye to these greasy smears.
The secret according to them lies in a coating layer containing special additives which is both water and oil repellent.
According to the scientists, when the particles integrated in the coating settle on the surface of the stainless steel, the surface becomes rougher and its surface area increases.
When a finger comes into contact with the refrigerator door, it only touches the raised points on the surface and the grease on the fingertip never reaches the ‘valleys’ of the stainless steel surface.
The new coating ensures that the surface area which actually comes into contact with the grease is kept very small.
In addition, the refractive index of the coating has been adjusted so that it matches that of the skin’s natural oil content.
This means light is reflected by the coated stainless steel surface in about the same manner as by a surface that has been touched by sticky fingers. As a result, the fingerprints are hardly noticeable.
According to IMWS research associate Dr Jessica Klehm, the research team has already started developing an automatic testing machine to assess the layers of the coated surface.
The device is not intended to investigate the particles in the coating, but rather the visibility of the fingerprints themselves.
The machine works by dipping a stamp in a solution whose composition resembles that of the oily film on human skin.
Using identical force and duration, the stamp is then pressed on the coated surface to leave behind ‘fingerprints.’
The machine will use a combination of spectrometric and optical procedures to analyzes how much of the solution remains on the surface.
This will help them to arrive at a percent value indicating the anti-fingerprint effect of the coating.
The scientists are currently working to find the ideal combination of analytical equipment for the purpose.
Image and content: Fraunhofer IMWS