Engineered 'Sand' Could be the Solution to Your Device's Heating Problems

Researchers from Georgia Institute of Technology had engineered "sand" that can be put in your Smartphone and other electronic devices to cool down these power-hungry devices with high heat fluxes.

The sand, described in a newly published paper in the journal Materials Horizon, is actually silicon dioxide nanoparticles coated with a high dielectric constant polymer.

For the study, the researchers first used water to coat the nanoparticles and turn the silicon dioxide nanoparticle bed into a conductor. However, the water coating is not robust, forcing the researchers to replace water with ethylene glycol, a kind of fluid most commonly used in vehicle antifreeze. The new ethylene glycol coating increased the heat transfer by a factor of 20 to approximately one watt per meter-kelvin, which can be comparable with the costly polymer composites currently used for heat dissipation.

"You could basically take an electronic device, pack these ethylene glycol-coated nanoparticles in the air space, and it would be useful as a heat dissipation material that at the same time, won't conduct electricity," said Baratunde Cola, an associate professor in the Woodruff School of Mechanical Engineering at the Georgia Institute of Technology and lead author of the paper, in a statement.

According to the paper, the secret behind the thermal conductivity of the newly engineered sand does not lie in the silicon dioxide itself, but in the unique surface properties of the coated nanoscale material. The combination of the silicon dioxide and the ethylene glycol as the coating produced a higher rate of heat transfer than each material can do by itself.

However, researchers noted that despite working so well ethylene glycol can eventually evaporate. Thus, researchers are setting to find other polymeric materials capable of being absorbed to the silicon dioxide nanoparticles to provide a more stable coating with a reasonable product time.

Furthermore, the researchers are planning to conduct a larger scale experiments involving larger amounts of silicon dioxide particles to see if the heat can also be transferred in a longer distanced in larger volumes of material.