Baratunde Cola, an associate professor at the Georgia Institute of Technology, has engineered sand-like silicon dioxide nanoparticles coated with a high dielectric constant polymer which when poured on the electronic devices, inexpensively provides improved cooling effect. According to the paper published in the journal Materials Horizons, the silicon dioxide does not do the cooling itself. Instead, the unique surface properties of the coated nanoscale material allows it to conduct the heat at potentially higher efficiency than existing heat sink material. And this thereby improves head dissipation from power electronics, LEDs and devices with high heat fluxes.
As researcher puts it, the theoretical physics behind the phenomenon is complicated as it involves nanoscale electromagnetic effects created on the surface of the tiny silicon dioxide particles acting together. “We have shown for the first time that you can take a packed nanoparticle bed that would typically act as an insulator, and by causing light to couple strongly into the material by engineering a high dielectric constant medium like water or ethylene glycol at the surfaces, you can turn the nanoparticle bed into a conductor,” said Baratunde Cola, in a news release. “Using the collective surface electromagnetic effect of the nanoparticles, the thermal conductivity can increase 20-fold, allowing it to dissipate heat.”
At first, the researchers experimented with water to coat nanoparticles and turn the silicon dioxide nanoparticle bed into a conductor. Unfortunately, the water coating was not sturdy. The researchers then decided to switch to ethylene glycol as a heat dissipation material that at the same time, did not conduct electricity. The ethylene glycol worked well, but it eventually evaporated. For this, Cola plans to identify polymeric materials that could be adsorbed to the silicon dioxide nanoparticles to provide a more stable coating.