Self-washing windows: China has learned to clean glass with an electric field

Chinese scientists from Zhejiang University has developed a self-cleaning glass using an electric field to dust removal and other particles from the surface. 

Particles contaminate all surfaces, from windows to building facades and solar panel surfaces. Their removal usually requires money, time, and considerable effort.

In their experiments, Chinese researchers have demonstrated that charged particles under the influence of an alternating electric field do not just move sideways, but change direction or even bounce off the surface. Many modern cleaning methods are ineffective in conditions of high dryness and a significant amount of dust. Technologies such as electrodynamic screens installed on rovers have the potential to remove dust without the need for a corresponding liquid or abrasive impact. 

However, their effectiveness was limited by a lack of understanding of how particles move or separate from the surface. In the absence of clear physical models, scientists had to look for optimal designs. The existing systems are still unable to effectively remove fine dust, especially if the coating is uneven.

By studying how particle size and electric field strength affect this movement, Chinese researchers have created a thin 0.62 mm thick transparent glass that can self-clean from organic and inorganic particles without the need for human intervention. This transparent glass is able to clean itself in a matter of seconds, removing 98% of particles without the use of water, chemicals, or significant energy consumption.

The development of Chinese scientists could lead to the emergence of a commercial self-cleaning glass and can be used, for example, as a surface for solar panels and windows in high-rise buildings. This self-cleaning glass not only removes dirt and dust, but also prevents their reappearance. Scientists have determined that the electric field repels charged particles in the air and prevents them from settling on the surface.

The researchers called this the “particle shielding effect,” which reduces the accumulation of dust in the air by 90%. This provides constant protection in sandstorms and high dust concentrations. Due to its transparency, glass is well suited for places where good lighting is important. It only slightly attenuates visible light, with most losses occurring in the infrared range.

This glass is ideal for solar panels, cars, roofs, greenhouses, and windows of high-rise buildings. The production process includes etching electrodes on a glass plate and coating them with a thin protective film without the need for expensive equipment. 

The results are published in the journal Advanced Science

Source: Interesting Engineering