Engineers at Oregon State University (OSU) have found a new way to induce and control boiling bubble formation that may allow everything from industrial-sized boilers to advanced electronics to work better and last longer.

According to the researchers, the concept could be useful in either of two ways: to boil water and create steam more readily, as in a boiler or a clothing iron, or to release heat more readily from a product such as an electronic device, allowing it to operate at a cooler temperature.

The new approach is based on the use of piezoelectric inkjet printing to create hydrophobic polymer “dots” on a substrate and then deposit a hydrophilic zinc oxide nanostructure on top. The zinc oxide nanostructure grows only in the area without dots. By controlling both the hydrophobic and hydrophilic structure of the material, bubble formation can be controlled and manipulated precisely for the desired goal.

Researchers show their ability to control bubble formation by spelling "OSU" on a substrate. Image credit: OSU.According to the researchers, this technology for the first time allows control of both the boiling and condensation processes, as well as spatial bubble nucleation sites, bubble onset and departure frequency, heat transfer coefficient and critical heat flux.

“One of the key limitations for electronic devices is the heat they generate, and something that helps dissipate that heat will help them operate at faster speeds and prevent failure,” says Chih-hung Chang, professor of electrical engineering. “The more bubbles you can generate, the more cooling you can achieve."

“On the other hand, if you want to create steam at a lower surface temperature, this approach should be very useful in boilers and improve their efficiency," he adds. "We’ve already shown that it can be done on large surfaces and should be able to scale up in size to commercial use.”

In terms of electronics, the engineers say this technology may have applications with some types of solar energy, advanced lasers, radars and power electronics—anywhere it is necessary to dissipate high heat levels. Another significant potential application of the technology is in creating more efficient operation of the steam boilers used to produce electricity in large electric generating facilities.