Evaporative cooling Inspired by Bees

Peter Gruber of IBM Research filed US Patent 4,549,407 in 1984 relating to "Evaporative cooling particularly useful for semiconductor integrated circuits is more efficient when a liquid is completely evaporated at the heat radiating surface. The liquid is converted to droplets and mixed with the gas at the heat radiating surface."  Although the patent does not mention any biomimetic origins, I received the following in a private communication. 

I definitely remember the process that led to this patent, since it was my first of over 100 while at IBM.  As a teenager I had read a book on beekeeping that was in our family library - we also had an apiary for a few years.  I believe it was titled "The ABCs of Beekeeping" or something like that.  In any case, several paragraphs chronicled an incident of a beehive set up close to a lumber yard, the lumber yard catching fire, some of the beehives catching fire too, and while the hive exteriors were charred, the combs did not melt.  This meant the bees kept a tremendous temperature differential from exterior to interior of the hive, and did this by adding water droplets in addition to the regular fanning that produces forced convection.

Years later, when I was a IBM Research, my team was working on high performance cooling, using both forced air and water cooling.  I remembered the book, referenced it again (incl a photo of the charred hives), and used this info to set up some phase change cooling experiments.  Unlike either air or water cooling, evaporative cooling produced temperature drops at the measurement surface below the temps of either the air or water supplies, confirming the efficiency of phase change cooling.  The results led to the invention disclosure, in which I believe I referred to the bee cooling reference.

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