Using silicon lithography, liquid silicone, and electrodes that are fashioned into patterns that are invisible to the naked eye, researchers at Stanford University have finally created the seminal sci-fi component that we’ve all been waiting for: transparent batteries.

The batteries are created by first etching very narrow channels, in a grid pattern, into a silicon wafer using standard lithographic processes. Liquid PDMS (a transparent silicone polymer) is then poured over the silicon wafer mold and cured. The electrode chemicals are dripped into the molded narrow channels and capillary action draws the chemicals into long, thin ridges. One piece of polymer is covered in positive electrodes and the other is covered in negative electrodes, and they’re perfectly aligned so that light passes through the gaps in the grids. The package is then filled with a clear gel electrolyte, wires are attached, and voila: a transparent battery!



The transparent battery powering an LED

The batteries don’t store a lot of power yet — about 20 watt-hours per liter of electrolyte, the same as a nickel-cadmium battery — but chief researcher Yi Cui says that the batteries should, in theory, be able to store about half as much power as a standard, opaque lithium-ion battery. A denser electrode pattern would produce more electricity, but sacrifice transparency — or you could simply line up a few transparent cells in the same way that most batteries use a series of cells to produce more power.

The applications for transparent batteries are numerous and far-reaching. A transparent iPhone 6 would obviously be rather fun, but hardly life-changing. Transparent, flexible OLED displays are a much more exciting prospect — and perhaps see-through laptops are the key to passing ever-tightening airport security measures. Ultimately, see-through batteries could usher in a complete range of transparent gadgets, from wrist watches to LED torches, to tablets, smartphones, and e-readers that let you keep an eye on the ground while you walk. Next-generation laptops or Nintendo and Sony portables could even use a clear body that allows daylight to illuminate the display…

Read more at Technology Review and Stanford University