Forget the elusive white iPhone. Yi Cui, an engineering professor at Stanford University, imagines a transparent iPhone.
Together with graduate student Yuan Yang, first author on a recent paper in the Proceedings of the National Academy of Sciences, Cui developed a transparent battery -- potentially the final component needed to make fully transparent electronics. "If the batteries were not transparent," Cui said in an interview, "then the device wouldn't be transparent."
Because the key components of batteries cannot be replaced or made transparent, Cui used a trick of the eye to develop the battery. He created a mesh-like framework for the battery electrodes. "Each line in the grid is smaller than 50 microns," he said. "When a human being looks at an object that's smaller than 50 microns, it's not visible. That's how we make it transparent."
The team found a transparent alternative to copper and aluminum in polydimethylsiloxane, a compound used in contact lenses, according to a news release. They deposited metals onto the rubbery material to make it conductive and poured it into molds to build the transparent grids. Yang created a transparent substance that served as both an electrolyte and a separator and inserted it between the electrodes, creating a functional battery. "It's completely new," Cui said.
Now, the researchers are working to increase the capacity of the transparent battery, which is only about half as powerful as its lithium-ion counterparts. And they're hoping others take notice. "We'd like industry to pick up our concept," Cui said, "and do the commercialization of these transparent batteries."
From there, the possibilities are varied. "Imagine you have a watch that you want to look transparent," Cui said. "You can have your iPhone be transparent. You can have your laptop be transparent."
Watch a video about the transparent batteries.
Photo: Transparent battery