A revolutionary paint that heats or cools buildings without wasting energy and is inspired by chameleons.

We’re in that confusing time of year when it feels like the temperature has already started to take its toll. descent into winter, suddenly they rise again. This is in the northern hemisphere, of course. In the south it’s the other way around. One thing is clear: it is difficult air conditioned buildings. Air conditioning or heating? Tough decision. Whatever we choose, it is clear that, just like in the middle of summer or in the middle of winter, the energy costs are enormous and the consumption fossil fuel, a big problem. Therefore, a group of scientists from Harbin Engineering Institutein China developed an alternative inspired chameleon skin.

In particular, they chose Namaqua chameleon (Chameleo namakensis), an African species very well adapted to living in desert areas. He desert It is a rather hostile place to live, as it can go from sweltering to freezing in the same day. Therefore, animals and plants living there must have mechanisms that allow them to withstand these influences. sudden changes in temperature. The authors of this study, which was just published in the Journal of the American Chemical Society, thought this made them a great source of inspiration for more efficient air conditioning of buildings, so they examined several species until they concluded that this chameleon was perfect.

It adapts to temperature, as chameleons do best: color change. When the environment is very warm, they become light gray which allows them to reflect heat. Just like when we paint a house white. On the other hand, when it starts to get colder, they take on a darker shade. dark brown, which absorbs as much heat as possible, preventing them from freezing to death. All this is known. In fact, there are already inventions based on color that have been aimed at air conditioning buildings. But no one thought of changing the tone the way a chameleon does.

A look at the chameleon for building air conditioning

These scientists wanted to create a paint that could change color, just like a chameleon does. To do this they relied mainly on thermochromic microcapsules. Thermochromy is the ability of a substance to change color with changes in temperature. Like typical cups that have a pattern appearing when you add a hot drink.

These microcapsules were combined with paint-specific microparticles and a binder that allowed the ingredients to mix well. Thus, suspense they can be sprayed or brushed on like paint. After they applied the paint to the air-conditioned buildings, they applied it to a metal surface, which was then exposed to various temperatures. These were from 68, 86 and 175 degrees Fahrenheit Or what’s the same thing 20°C, 30°C and 79.44°C.

The paint was originally dark gray, but became lighter as it warmed, so that at 86°F it reflected 93% of solar radiation. At 175°F, it not only reflected radiation, but also He did not suffer any damage.

Also outdoors

Following these experiments, plein air painting was used on a miniature building the size of doghouse. To compare the results we also used regular white paint, passive radiant cooling paint, and some blue metallic tiles.

Thus, it was observed that in winter their paint warmed the house slightly more than radiant-cooled paint, although the temperatures were very similar. In the summer it was much colder than white paint and metal tiles. But above all in spring and autumn temperature fluctuations.

All this will allow buildings to be air-conditioned all year round in an efficient, clean and, obviously, profitable way. We’ll have to do a little more research, but maybe our homes will be inspired by chameleon skin in the future. Of course, looking at nature is interesting for many reasons, and not just to decorate the eyes.