Researchers at Stanford University have created what is thought to be the world's first transparent battery, indicating that invisible devices may be an imminent possibility.
Inside the lithium-ion battery is a tight mesh of electrodes that are so tightly packed that they appear invisible to the naked eye and the outside is made of a fully transparent polymer called Polydimethylsiloxane (PDMS). The result is a thin, flexible, barely visible battery.
With transparent displays already in development for televisions and phones, making the inner workings equally as see-through was the next logical step.
Now you see me, now you don't
At the moment these batteries only have about half of the energy of a regular battery, but further development could improve on that.
Yi Cui, a developer from the project, said: "Its cost could be similar to those of regular batteries, especially if we use low cost metals"
There are a number of applications that this new transparent battery could have, particularly being able to study what is happening inside batteries while they are at work.
The designers have filed for a patent but Mr Cui has set his sights on big things: "I want to talk to Steve Jobs about this. I want a transparent iPhone!"
But sure, fully transparent phones sound good in theory - as long as you remember where you put them.
Check out the video of the transparent battery from Stanford University below.