Researchers discovered why some ultra-small heat sources cool down faster if you pack them closer together. The discovery could help industries design faster electronic devices that overheat less.
Heat is one of the major enemies of electronic devices, and therefore, thermal management is a challenging consideration in designing electronics. Excessive heat in electronic devices can degrade their performance, and can make the devices work in an unstable manner. It is important to understand the fundamental physics involved in heat dissipation and efficiently manage the flow of heat.
Researchers from University of Colorado at Boulder discovered the fundamental reason why some ultra-small heat sources cool down faster if they are packed closely together. They experimented on ultra-thin bars of metal on silicon substrate, and heated those bars up with a laser.
“They behaved very counterintuitively,” study co-author Joshua Knobloch, postdoctoral research associate at JILA, a joint research institute between CU Boulder and the National Institute of Standards and Technology (NIST), said. “These nano-scale heat sources do not usually dissipate heat efficiently. But if you pack them close together, they cool down much more quickly.”
In this study, the researchers used computer simulations to track the passage of heat from their nano-sized bars. They observed that when they spaced their silicon bars far enough apart, heat tended to escape away from those materials in a predictable way. In this case, the energy leaked from the bars, dissipating in all directions.
But when the bars were closer together, the heat from those sources scattered. It effectively forced that energy to flow more intensely away from the sources. The team denoted this phenomenon “directional thermal channeling.”
“This phenomenon increases the transport of heat down into the substrate and away from the heat sources,” Knobloch said.
The researchers believe that their discovery could highlight a major challenge in designing the next generation of tiny devices, such as microprocessors or quantum computer chips:
The research ‘Directional thermal channeling: A phenomenon triggered by tight packing of heat sources’ appeared in the journal Proceedings of the National Academy of Sciences.
