Triboelectric effect can reduce the spread of air pollutants through ventilation

Wed 10 Jan 2024 09:00

A new cellulose-based filter material acting as a self-charging filter can provide more effective protection against polluting particles that threaten public health and safety. Now researchers at Mid Sweden University will investigate how much benefit such air filter concept can do.

AI generated image showing a hand holding an air filter and viruses surrounding the filter.

The four-year research project ”Tribofilter” was recently granted close to four million SEK by the state research council Formas.

– The Covid-19 pandemic clearly showed how important it is to contribute in various ways to reducing the spread of airborne viruses. In addition to viruses, many other air pollutants are harmful to health when inhaled. By investigating the effect of triboelectric phenomena on the filtering efficiency of cellulosic materials, we want to design a more effective air filter system for indoor ventilation and contribute to securing safe and clean air for everyone, says Alireza Eivazi, project leader and researcher in surface and colloid engineering research group.

The fact that diseases and illnesses occur in people due to inhaling pollutant particles that are harmful to health is a well-known phenomenon. Annually, it is estimated that around seven million people around the world die as a result of various diseases and illnesses caused by air pollution.

– In indoor environments, ventilation with protective filters is used to clean the air. The conventional filter materials used today are made of oil-based synthetic materials with limited filtering capability. To improve filtering efficiency, they must be very dense filters with low flux to capture the pollutants, which means that the air purification is not very energy efficient. Besides, they are not environmentally friendly and thus cannot be disposed of in nature, meaning the used ones can be a secondary source of environmental pollution, says Alireza Eivazi.

The research group at Mid Sweden University therefore suggests a new cellulose-based filter material with high particle retention and low-pressure drop based on the triboelectric effect. The developed material is thought to act as a self-charging filter that retains polluting particles harmful to humans.

– If we use the triboelectric effect, the particles will be drawn to the charged surface and thus stick to the filter material, allowing us to have protective filters that let more air through. Therefore, the effect should lead to better filtration with reduced energy use while minimizing the spread of harmful particles, says Christina Dahlström, associate professor and member of the research group.

– We work in several different areas where we combine the triboelectric effect with cellulose-based material. We have discovered that it is possible to design filters that become self-charging if different layers of the material are allowed to come into contact with each other through vibrations arising from the airflow itself. The use of renewable cellulose, instead of oil-based material, is also in line with several goals in the UN's agenda for sustainable development, says Magnus Norgren, professor of chemical engineering.


Alireza Eivazi, project leader and researcher in surface and colloid engineering research group, +46 10-142 83 70,


The page was updated 1/10/2024