Why there are always so many fingerprints on the phone display and how to clean them

The smartphone has become an integral part of our days. We use it in an infinite number of contexts and to carry out the most disparate operations. Since modern smartphones work via touch screen technology, your fingers constantly come into contact with the screen. Therefore, fingerprints accumulate on the displays of our smartphones due to the fats naturally present on our fingertips.

Even though the screens of modern smartphones are equipped with a oleophobic coating which avoids theexcessive accumulation of fingerprints on its surface, it must be said that this tends to deteriorate over time, reducing its ability to not retain fingerprints. Furthermore, if you apply screen protectors without an oleophobic coating, they are more likely to get dirty. To clean fingerprints while preventing the oleophobic treatment from degrading, the best choice is to wipe the screen with a dry microfibre cloth or using a less aggressive product.

How the oleophobic coating on your phone screen works

The olephobic coating (defined by some smartphone manufacturers oleophobic), now present on all smartphones in circulation, consists of a particular layer of coating which has the function of protecting the screen, improving smoothness and, clearly, reducing the probability of fingerprints being deposited on the surface of the display. The etymology of the term oleophobic allows us to understand very clearly the meaning of the term, which derives from Greek

How is the oleophobic coating on the screens made? It is generally made with a thin layer of fluoropolymer-based materialswhose properties allow us to repel oil and fat residues present on our fingertips which, otherwise, would easily deposit on the surface of the screen.

As was explained by the science communicator Bill Nye in an article published on Gizmodo a few weeks after the presentation of theiPhone 3GS – the first smartphone to integrate a display with oleophobic treatment, announced way back in 2009 – this technology is created by exploiting some chemical properties that repel oils. To go into more detail, Nye reported:

Researchers (from Apple, Ed.) managed to achieve this result by gluing this oleophobic polymer to glass. The polymer is an organic compound (coming from organisms), based on carbon. Glass is nominally inorganic, silicon-based… a solid rock. The trick is to get one to stick to the other. (…) This probably happens with a third molecule that attaches to silicon on one side and to carbon-based polymers on the other. Chemical engineers get it to stick by causing the compounds to diffuse or “interpenetrate” into the polymer. The intermediate chemical is a “silane”, a molecule that contains silicon and alkanes (chains of carbon atoms). (…) The polymer that coats the iPhone 3GS screen doesn't let oil from your skin stick to it. The key lies in the intermediate compounds, the silanes that bind the plastic to the glass.

“Translated” in simple terms, therefore, the oleophobic coating present on smartphones is made in such a way that, from a chemical point of view, there are not the right conditions for the oil and grease residues present on the surface of the smartphone to “stick” to the screen. our skin.

What to do if your phone screen gets dirty and how to remove fingerprints

Unfortunately, the oleophobic coating is not eternal and tends to wear out over time. Smartphone manufacturers are clearly aware of this and even admit this problem on their official documents.

Applefor example, on a help page on its official website states:

iPhone has an oleophobic (oil-repellent) coating that resists fingerprints. This coating will wear over time with normal use.

As time passes, therefore, it is practically physiological that the oleophobic coating degrades and is less effective in avoiding the accumulation of fingerprints on the screen. To prevent this from happening prematurely, however, it is important do not use aggressive products to clean the screen, such as those containing bleach or hydrogen peroxide (those containing 70% isopropyl alcohol or 75% ethyl alcohol are usually approved by manufacturers). In reality, to be honest, if the oleophobic coating is intact, to clean the smartphone screen you just need to use a simple microfibre cloth.