Researchers at the Massachusetts Institute of Technology (MIT) developed revolutionary passive cooling system. Using only water, it provides 9.3°C cooling in direct sunlight.

This technology is based on a three-layer structure consisting of a solar reflector, a bundle of evaporator and emitter, and an insulating layer. The design allows heat to be removed and water to be cooled inside the material.

Illustration: MIT

The top layer is made of airgel with many cavities filled with air. This insulating material transmits water vapor and infrared radiation. The second layer is made of hydrogel, in the cavities of which there is already water. Finally, the last layer is a mirror. Two layers look like a pancake about 20 mm thick:

Illustration: Zhengmao Lu / MIT

Everything works by reflecting light and infrared radiation through two layers of gel. As a result, the heat that may have warmed the food box is removed and the contents of the container remain cool. The researchers say that in humid conditions, the technology can keep food up to 40% longer than a similar container without a refrigeration system.

The idea itself is not new. Even in ancient times, people dug holes in the ground to protect food from the sun’s rays. However, the current version does not require digging holes or building underground bunkers, which could open up new possibilities for storing food and other items that need cooler temperatures.

The commercial application of this technology is still far away. The gel, created by scientists for experiments, is quite expensive to manufacture. If they manage to change the composition so that it becomes cheaper, but has the same properties, it will be possible to talk about scenarios for real use.

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