An engineer has developed a new method for removing excess heat
The researcher has developed a planar bridge thermal diode that allows you to effectively control the thermal regime of electronics, aircraft and even spacecraft..
A team led by Jonathan Boreiko, assistant professor of mechanical engineering at Virginia Tech, created a device of two copper plates in a sealed environment, separated by a microscopic gap. One plate has a wick structure to retain water and the other is covered with a water repellent layer.
When the water on the absorbent surface heats up, it begins to evaporate. When As steam passes through the narrow gap, it cools and condenses on the hydrophobic side. These droplets grow large enough to «overlap» gap, and are sucked into the wick again, starting a new cycle.
If the heat source is on the hydrophobic side, then steam cannot be generated, as water remains in the wick. Therefore, the device can only conduct heat in one direction..
In practice, when a diode is connected to an overheating object, the generated heat is transferred through the conductive plate to the water, which turns into steam and is removed from the source. The hydrophobic non-conductive side prevents heat from entering air or other heat sources that may be nearby, allowing the diode to drive heat only from its primary object.
Scientists have also recently developed paint that can cool buildings by reflecting up to 98% of incoming heat..
text: Ilya Bauer, photo: Virginia Tech