Researchers at the National University of Singapore have developed a new two-phase technique they say is up to 50 percent more effective in cooling electronic systems compared to current cooling technology.
Led by Lee Poh Seng, Ph.D., of the Department of Mechanical Engineering at NUS, the team combined microgap and stepped fin microchannel heat sinks to create a two-phase heat dissipation system based on the flow-boiling concept. First, the liquid coolant flows along the system and enters the microgaps, where it picks up heat. When it reaches the boiling point, the coolant changes from its liquid state to a vapor, absorbing the latent heat during this phase-change process, Seng explained, adding that the surface of the microgaps are designed specifically with an ideal texture to help the formation of vapor bubbles. The microchannels further enhance the rapid dissipation of heat.
“For the system to work well, two main factors have to be taken into consideration—the size of the gaps and the texture of the surface of the gaps through which the coolant flows,” Seng said. “We spent many long hours monitoring the boiling regime using special high-speed cameras. Through the recorded videos, we managed to extract data for us to design microgaps that are of the optimal size and surface texture to allow the cooling process to take place rapidly and effectively.”
The new technique is more reliable, cost- and energy-efficient than current cooling systems, say the researchers, and can be used to cool both personal electronic devices and larger electronic systems. Furthermore, the technique can also be applied to electronic systems operating in compact spaces, as it does away with the need for large cooling fans.
The team plans to produce a prototype of their concept by early next year using a $250,000 USD proof-of-concept grant awarded to them by the National Research Foundation in February 2013. Related research can be found on the Micro Thermal Systems Group’s webpage.