16 MOMENTUM • VIRGINIA TECH MECHANICAL ENGINEERING
Novel method of heat conduction could be a game changer for server farms and aircraft
Jonathan Boreyko , an associate professor in mechanical engineering , has developed an aircraft thermal management technology that stands ready for adaptation into other areas .
The research was published in Advanced Functional Materials on Aug . 18 , 2020 .
Boreyko was the recipient of a Young Investigator Research Program award in 2016 , given by the Air Force Office of Scientific Research . This award funded the development of planar bridging-droplet thermal diodes , a novel approach to thermal management . Boreyko ’ s research has shown this new approach to be both highly efficient and extremely versatile .
“ We are hopeful that the one-way heat transfer of our bridging-droplet diode will enable the smart thermal management of electronics , aircraft , and spacecraft ,” said Boreyko .
Diodes are a special kind of device that allow heat to conduct in only one direction by use of engineered materials . For management of heat , diodes are attractive because they enable the dumping of heat entering one side , while resisting heat on the opposite side . In the case of aircraft ( the focus of Boreyko ’ s funding ), heat is absorbed from an overheated plane , but resisted from the outside environment .
Boreyko ’ s team created a diode using two copper plates in a sealed environment , separated by a microscopic gap . The first plate is engineered with a wick structure to hold water , while the opposite plate is coated with a water-repelling ( hydrophobic ) layer . The water on the wicking surface receives heat , causing evaporation into steam . As the steam moves across the narrow gap , it cools and condenses into dew droplets on the hydrophobic side . These dew droplets grow large enough to “ bridge ” the gap and get sucked back into the wick , starting the process again .
Boreyko ’ s approach : heat applied to the water attracting plate opposite the hydrophobic plate .
Boreyko ’ s approach : heat applied to the water attracting plate opposite the hydrophobic plate .
If the source of heat were instead applied the hydrophobic side , no steam can be produced because the water remains trapped in the wick . This is why the device can only conduct heat in one direction .
What does this look like in practice ? An object producing heat , like a CPU chip ,