In order to have a truly flexible device, a flexible OLED display is not enough - all the rest of the components must also be flexible. Researchers from the Korean Advanced Institute of Science and Technology Institute (KAIST) have managed to develop a high-performance Lithium-ion flexible battery.
The researchers structured the Lithium-Ion with high density inorganic thin films by using a universal transfer approach. They fabricated the battery on a mica substrate (at high annealing temperature) and then transferred it onto polymer substrates using a simple physical delamination of sacrificial substrates. They are currently trying to use a laser lift-off technology to facilitate the mass production such batteries and also enable stacking the structures to enhance the density.
KAIST says that recent advances in flexible display has motivated their research into more flexible components. In 2011 they have developed a flexible non-volatile resistive random access memory (RRAM) on plastic.