Cotton that disinfects itself with ordinary lamplight, tested in a hospital

In a hospital, many people with a weak immune system are together in one place. For them, a bacterium that stays on a sheet or bed rail can cause a dangerous infection. Cleaning helps, but textiles become contaminated again and again over the course of the day. What if the fabric kept itself clean?

Researchers at the Universitat Politècnica de València (UPV) in Spain have made such a fabric. It is ordinary cotton, with a special finish. As soon as light falls on it, the fabric makes bacteria, fungi and other microbes harmless. The team worked with La Fe hospital in Valencia and described the research in the scientific journal ACS Applied Materials & Interfaces.

How it works

The researchers apply two dyes that react to light to the cotton in layers. Other substances in those layers attach the dyes firmly to the fibres.

When light falls on the fabric, the dyes capture that energy and pass it on to the oxygen in the air. That oxygen is briefly 'charged up' as a result. This makes the oxygen molecules react much more easily with other substances. In this way they damage the microbes sitting on the fabric, so that they die. You can compare it to a solar panel: that turns light into electricity, while this fabric turns light into a disinfectant, exactly where it is needed.

The special thing is that ordinary white light is enough, the light from the lamps that already hang in hospitals. According to the magazine New Atlas, earlier materials of this kind often needed blue or ultraviolet light.

Results in the lab and in the hospital

In the lab, under light, the gut bacterium E. coli was made completely harmless within an hour. For the bacterium Enterococcus faecalis, a well-known cause of hospital infections, it took twenty minutes. The yeast Candida albicans also decreased considerably within three hours.

The team then tested the fabric in practice, in the rooms of twelve patients at La Fe hospital. For two days, pieces of fabric lay on the bed rails, where a lot of light falls, and on the mattresses, where it is darker. For comparison, ordinary cotton lay in the same places.

In the places with light, 75 per cent fewer microbes remained on the new fabric than on the ordinary cotton. For one group of bacteria, the so-called Gram-positive bacteria, it was even 77.5 per cent fewer. On the mattresses, with little light, the difference was 25 per cent. That shows clearly how the fabric works: the more light, the better it disinfects itself.

Even after washing

Hospital textiles are washed often and at high temperatures. That is why the researchers washed the fabric twenty times. After that, it still worked better than the standard that applies to antimicrobial textiles.

According to the researchers, the finish fits into the existing ways in which factories dye and finish textiles. That makes large-scale production possible. The hospital trial was still small, with twelve rooms. The next step is testing on a larger scale and finding out how the fabric can best be used, for example in covers, curtains or clothing for healthcare staff.

We wrote earlier about another clever cloth, which protects strawberry plants from insects. There too, ordinary textile gets an extra job.

What does this mean for the road to the singularity?

More and more ordinary materials are getting a smart function. A fabric that keeps itself clean with lamplight is a good example: no extra device, no extra cleaning product, only light that is already there.

There is also an opportunity for AI here. There are thousands of dyes that react to light, and countless ways to attach them to fibres. AI models can help find the best combinations, and bring together knowledge from different fields: from chemistry and textile engineering to microbiology and hospital hygiene. In this way, a clever discovery like this can find its way faster to the beds and corridors of hospitals.

What is the technological singularity? Read the explanation →