Stanford University researchers have now created see-through lithium-ion batteries; when combined with transparent screens, keyboards, and circuitry, manufacturers may be able to create fully transparent electronic devices. So soon, rather than searching frantically for those set of keys you somehow misplaced, you can spend your time trying to find your see-through cell phone sitting right in front of you.
Scientists usually make devices like solar cells appear translucent by creating ultra-thin versions of their components. But this doesn’t work with a battery because its electrodes need to be thick enough to store a decent amount of energy. So, the Stanford researchers, in their study recently published in the journal Proceedings of the National Academy of Sciences (pdf), took a different approach: they created lithium-ion electrodes out of components too small for the naked eye to see.
Essentially, the team made an electrode grid housed in PDMS, a flexible and clear polymer often found in contact lenses, and wrapped it all in plastic. The researchers created a functional battery when they stacked two of the electrodes on one another (with a clear electrolyte gel in between for conductivity and separation). The lines of the grids were each only about 35 microns thick (the maximum resolving power of the human eye is between 50 and 100 microns), and there was enough electrode material in the grid trenches that the battery could store about half of the energy a normal lithium-ion battery of the same size could. The batteries were able to let about 60 percent of all light pass right through them.
But why would anyone even want transparent batteries and devices?
There are several practical reasons. First, the see-through components will allow researchers to actually study the chemical reactions going on inside the batteries, as they are happening, something scientists couldn’t previously do. Additionally, the technology could help reduce the size of portable devices (as if our cell phones weren’t small enough already), chemist Hiroyuki Nishide told Nature. And as LiveScience points out, the transparent batteries could be useful for augmented reality—say, a clear iPad that lets you virtually superimpose images onto the world around you.
But maybe you don’t care about any of that. Maybe, like lead research Yi Cui, you think a transparent device would be just plain cool. “I want to talk to Steve Jobs about this,” Cui said in a Stanford news release. “I want a transparent iPhone!”