Time seems to slow down. A coffee cup empties onto a keyboard, a glass full of water falls against a laptop, a smart phone sinks to the bottom of a toilet.
While some electronic devices just need airing out, others require serious repair or even replacement. Korean scientists have come up with a way to make hardware truly spill-proof.
"This is a kind of new approach combining nanowire superhydrophobicity with next-generation memory devices," said Kijung Yong, a chemical engineering professor at the Pohang University of Science and Technology in South Korea who led the research. He and his colleagues Seunghyup Lee and Wooseok Kim recently published their technique in the journal Advanced Materials.
Yong's lab researches nanomaterials and their applications for electronics, including tiny next-generation memory devices used in nanoelectronics. His group has also spent several years using nanowires to fabricate "superhydrophobic" surfaces, meaning they cause water to bead up and bounce off. This is the same phenomenon that naturally occurs on lotus flowers.
One day, it struck Yong that he should try to combine these two areas of research: create next-gen devices with superhydrophobic surfaces. In the lab, Yong and his colleagues constructed a resistive switching memory device covered in nanorods made from zinc oxide.
Each tiny rod was placed on the device's surface like a bristle. Together, the aligned nanorods acted like the waxy layer of a plant. The nanorods, separated by pockets of air, kept water droplets off the device like a crowd bouncing beach balls overhead.
"Our experiments showed that this new concept works very well," he said, adding that other waterproof coatings exist but require relatively complicated processes to make. Yong's straightforward method, however, allows chemical engineers to easily create dry surfaces with well-placed nanorods.
"Everybody knows water is fatal in operation of electronic devices," Yong said. "Our work suggests the possibility of overcoming the water vulnerability of electronic devices."
Next, Yong says his research group will work on improving the effectiveness of the nanocoating when the device is completely submerged underwater.
Yushan Yan is an engineering professor in the chemical engineering department at the University of Delaware who specializes in thin-film coating research.
"What they did that was really interesting is applying the coating to a working device. The device is not fancy, but nonetheless it's a device," he said. "For the field, this goes one step forward toward a real application."
Years ago, Yan's mobile phone accidentally got dropped in the toilet. He had to open it up and dry it out. "The phone survived, to the credit of the design engineers," he said. "Perhaps with this new technology you could take it out and not need to shake it because the water never even got in there."