Just recently, on April 12th, Electronics Cooling reported on “new” cooling technique called superwicking. They were reporting on an article from Science Magazine entitled, “Toward Liquid Cooling Computers“.
The notion of superwicking is certainly an exciting development and worthy of further exploration to find its right niche for a given cooling application. We asked Dr. Kaveh Azar, the President of ATS, Inc, and someone many of our readers know from ATS’s Thermal Webinar Series, what his take was on superwicking. Dr. Azar told us that “for every cooling solution developed, there is a thermal problem in the electronics industry that would benefit from it, but there is no silver bullet and often the cooling solutions are application specific”.
Kaveh told us that though the concept of superwicking is relatively new, the parallels with microchannels are ironic. Microchannels received focus when scientists looked at the definition of the Nusselt’s number and realized that the heat transfer coefficient is inversely proportional to the hydraulic diameter; that is the smaller the hydraulic diameter the larger the heat transfer coefficient. That discovery convened a large amount of inconclusive research on microchannels with data not being duplicatable from one researcher to another. In parallel, much effort has been focused on the pumping technology to make the microchannels work since, as the hydraulic diameter gets smaller, the pressure drop increases exponentially. Yet, despite many promises and revolutionary cooling possibilities with microchannel, except for a few highly niche applications, the practical side of deployment has confined the microchannels to laboratory experiments and academic articles. [editor: we’ve covered Microchannel technology here at the ATS heatsink blog at three different articles here, here and here].
We asked Kaveh should the industry be excited about superwicking? His answer was a resounding, “Yes, from the engineering standpoint this is certainly a milestone. Being able to strongly wick liquids against gravity is an engineering accomplishment”. But Kaveh cautioned that translating this concept to cooling high-power chips or deployment in electronics cooling is a stretch and can actually mislead the inexperienced thermal engineer in the field. The practical application and deployment of super wicking into chips or system-on-chips is an entirely different challenge. In fact, it mandates not just resolving a superwicked structure on a chip but also its deployment in system. Thermal challenges in every electronic structure (whether chip, PCB or a system) have unique requirements and once deployed on a premise, a system is governed by the site’s requirements. Kaveh concluded his thoughts on superwicking by saying, “proclaiming superwicking can solve real world, high power applications and set the expectations for the technology high seems premature. We just need to look at the literature and see how far microchannels have gotten in cooling high power electronics ‘the data shows not far. But, ATS, Inc. strongly encourages and applauds the researchers in this area’ as thermal management sorely needs innovative and visionary ideas.”
