'Cooling Fans and Heat Sinks' Disappear...? Development of Energy-Zero Metal Cooling Technology

Professor Kim Seon-kyung's Team at Kyung Hee University Successfully Develops Nano-structured Metal Plate Inducing Heat Emission

(Figure 1) Conceptual diagram explaining the principle of metal cooling through thermal radiation and a photo of an actual copper substrate with a gap plasmon structure applied
(Left image) A metal structure exposed to sunlight absorbs the energy of sunlight, causing the surface temperature to rise. However, when a structure that induces thermal radiation is introduced on the metal surface, cooling occurs. At this time, the radiation emitted from the structure escapes into space through the atmospheric window.
(Right image) General camera image and infrared image before and after the introduction of the gap plasmon structure. When the gap plasmon structure is introduced, the emissivity increases, so it appears as a bright image in the infrared image. The gap plasmon structure is designed with five types of metal tiles of different sizes so that the radiation is emitted in the infrared region with wavelengths from 8 to 13 μm.
Figure description and provided by = Seonkyung Kim, Associate Professor, Department of Applied Physics, Kyung Hee University

[Asia Economy Reporter Kim Bong-su] In midsummer, automobiles, buildings, communication equipment, and solar cells exposed to strong sunlight require separate cooling devices such as heat sinks and cooling fans. This is because metals only absorb heat and do not emit it. However, a domestic research team has developed an ultra-thin metal plate with a nano structure that helps radiate (emit) heat. It is attracting attention for its potential to revolutionize metal cooling methods by eliminating heat sinks and cooling fans.

The National Research Foundation of Korea reported on the 16th that Professor Kim Sun-kyung’s team from the Department of Applied Physics at Kyung Hee University discovered that heat radiation on metal surfaces can be induced through a nano structure that promotes heat emission without consuming energy. In other words, instead of transferring heat with a thick heat sink, the principle is to cool the metal itself by introducing an ultra-thin metal plate with a nano structure that aids heat radiation. In outdoor solar exposure experiments conducted in winter (average ambient temperature 0°C), the team fabricated such thin metal plates and confirmed a cooling effect of about 4 degrees Celsius compared to conventional copper plates without the nano structure. Simulations assuming an average temperature of 25 degrees Celsius in summer predicted a cooling effect exceeding 10 degrees Celsius. The hotter it is, the greater the heat radiation energy, so the cooling effect is larger in summer.

The research team created a 'gap plasmon' structure by coating a widely used copper plate with 500-nanometer (nm) thick zinc sulfide and introducing square-shaped copper tiles on top. When a thin dielectric layer is coated on a metal plate and square metal tiles are placed on it, a gap plasmon phenomenon occurs where light strongly concentrates in the dielectric gap region. This gap plasmon helps the metal behave like a 'blackbody' (an ideal object with 100% thermal emissivity), enabling strong heat radiation even on the metal surface.

Unlike conventional cooling methods such as heat sinks or cooling fans, which are difficult to miniaturize and require separate energy, this principle could bring a major innovation to cooling methods for automobiles, buildings, communication equipment, and solar power panels. The research team explained, "This technology can be applied to all metals used in industry such as copper, aluminum, silver, and platinum, and it is thin and flexible, allowing attachment to metal heat sources of various shapes." The research results were published online on the 21st of last month in the international nanoscience journal Nano Letters.

This content was produced with the assistance of AI translation services.