Researchers from the ICN2 Institute in Barcelona and the ICMM in Madrid have developed a new silica microsphere material that can emit infrared radiation to cool another material without Consume any energy or produce gas. This result can be used for devices that have a significant impact on their performance as temperature rises, such as solar panels or computer systems.
Refrigeration is a central issue in today’s society. Whether in a supermarket or on a personal computer, temperature adjustment must be carried out to ensure that people or machines operate comfortably and reliably.
Refrigeration systems account for 15% of global energy consumption and 10% of greenhouse gas emissions. Since greenhouse gases cause global warming and even more cooling measures are needed, the cure may be worse than the disease.
Researchers at the Catalan Institute of Nanotechnology and Nanotechnology (ICN2) and the Madrid Institute of Materials Science (ICMM-CSIC) have developed a way out of this cycle.
Members of the ICN2 group Phonon and photonic nanostructuresLed by Professor ICREA Clivia M. Sotomayor Torres, In collaboration with the ICMM photonic crystal team, described a new type of two-dimensional material that can remove heat and cool the surface placed on it without consuming any energy or generating any form of gas.
The work has been published in small, with Juliana Jaramillo-Fernandez, Marie Slodowska-Curie COFUND postdoctoral researcher and first author of ICN2.
The material is inspired by the effective mechanism of earth temperature regulation, namely Radiant cooling. Although the earth is heated by the sun, it also emits infrared radiation into outer space because this radiation is not captured by the atmosphere.
The sand in the desert is the main reason for this phenomenon. As long as we don’t consider human factors, it can keep the average temperature of our planet stable.
The proposed material uses the same principle. Researchers have shown that it can cool silicon wafers to 14ºC under direct sunlight, while ordinary glass can only reduce the temperature by 5ºC.
Self-assembled sphere array
The material consists of a self-assembled matrix of silica spheres with a diameter of 8 µm, like sand grains one million times smaller in volume.This layer is actually an ideal infrared emitter, providing up to 350 W/m of radiant cooling power2 pcs Used on high temperature surfaces, such as solar panels.
Putting the data in context, this can remove half of the heat stored in a typical solar panel on a sunny day, which is enough to increase the relative efficiency of solar cells by 8%. Taking into account the global solar production in 2017, this increase in efficiency represents enough energy for the entire year to power the city of Paris.
Researchers have revealed the radiative cooling potential of self-assembled crystals, showing that single-layer microspheres are necessary for optimal performance. This fact has aroused great interest in its future applicability and production. This new material is six times thinner than current radiant cooling materials and avoids the use of plastics.
The potential impact of this technology has not been overlooked.Researchers Juliana Jaramillo, Achille Francone ÿ Nikolaos Kehagias The ICN2 team has also developed another easily expandable material that can provide radiant cooling and self-cleaning functions.
Collider,by Barcelona Mobile World Capital A project linking scientific research and entrepreneurial innovation has been awarded to the project 2019 Collider Technology Award. This award stimulates the future development of the research field of radiant cooling materials. ICN2 and ICREA registered a European patent to protect the intellectual property rights of this technology on July 31, 2019.
In addition to using it for solar panels, other possible applications include cooling thermoelectric modules (devices that convert temperature differences into electric current), cooling computer systems in data centers, and even cooling itself and the surrounding environment. Cool smart windows, thereby saving costs. air conditioning.
Juliana Jaramillo-Fernandez, Guy L. “Self-assembled two-dimensional thermal functional materials for radiant cooling”. small, 2019; 1905290. https://doi.org/10.1002/smll.201905290