Leave it to engineers to figure out how to improve something we’ve been doing for thousands of years.
Researchers at Oregon State University (OSU) recently discovered a way to generate bubble formation and, in turn, control boiling. This form of control could significantly improve how advanced electronics and industrial boilers function.
Better Bubbles for Better Boiling
The OSU engineers used a piezoelectric inkjet printer to create hydrophobic polymer “dots” on a substrate and then deposited a hydrophilic zinc oxide (ZnO) nanostructure on top of that. ZnO only grows in the controlled area without dots, since hydrophobic areas repel hydrophilic substances. Hence, by manipulating these structures, engineers can orchestrate bubble formation for whatever goals they desire.
In addition to the ability to control the boiling and condensation processes, spatial bubble nucleation sites (the initial formation of bubbles during which temperature is slightly above liquid temperature) could also be controlled for the first time, along with bubble onset and departure frequency, heat transfer coefficients and critical heat flux.
Applications for Improved Water Boiling
“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,” said Chih-hung Chang, professor of chemical engineering at OSU.
“[With] more bubbles generate[d], more cooling [is] achieved. 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. We’ve already shown that it can be done on large surfaces, and it should be able to scale up in size to commercial use.”
Electronics applications range from some types of solar energy to advanced lasers, radars, power electronics and applications in which controlling heat dissipation is needed. In the industrial sector, this research could improve the operational efficiency of steam boilers used in power generating facilities.
Other applications include steam generation for boilers or clothing irons, for example. In the case of electronic devices, reduction of overheating can prolong life. Overall, the new technology will bring about significant cost savings in a range of applications—something every engineer likes to hear.
The published results of the research are available under the title “Large-scale Generation of Patterned Bubble Arrays on Printed Bi-functional Boiling Surfaces” in Scientific Reports.