Not satisfied with a future vision that already includes flexible screens and wafer-thin phones, a pair of Japanese companies has pushed the envelope to come up with far-fetched gadgets that do all of the above without ever going near a power socket.

The key to the work by Mitsubishi Chemical and Sumitomo Chemical lies in so-called spreadable electronics – liquids containing molecules of the type used in OLED screens.

Two in one

Engineers like Tokitaro Hoshijima at Mitsubishi Chemical see the possibility of using spreadable electronics to create both ultra-thin displays and solar panels at the same time [subscription link].

Because solar cells and OLEDs work on similar, but opposite, principles, it is possible to make materials that both take light and turn it into electricity and also do the opposite to provide a controllable display.

Hoshijima and many others are working on a molecular soup that can be spread anywhere and then dried to leave a residue layer that is only 100nm thick. This currently forms the basis for their proposed solar cell.

World without plugs

He explains: "What I want to create is a world that does not need power sockets." He goes on to describe how his paste applied to the back of a phone could be enough to charge the device when exposed to light.

By the same token, researchers at Sumitomo Chemical have created a similar organic solution that can be sprayed onto a surface to create an OLED screen.

Such a display could be on a rollable piece of plastic or even applied directly to a wall. The solar-charging properties described above mean it would never need to be plugged in.

Blue-sky projects like these typically take years to bear fruit, but both companies are looking at getting usable prototype devices ready within the next two years.