A small thin super-flexible OLED display which can be wrapped around a pencil has been developed by Japanese giant Sony.
The organic thin film transistor driven, full color, OLED display is only 80 μm-thick and just over 4 inches wide. It is able to reproduce moving images while being rolled around a cylinder with a radius of 4 mm. Even after 1000 cycles of repeatedly rolling and stretching the thin flexible panel, there was no visible deterioration in the display's ability to reproduce the moving images.
Photo of OTFT-driven OLED display wrapped around a cylinder with 4 mm radius (moving image can also be reproduced).
The roll-up capability was possible due to the rigid driver IC chips which were removed from the display.
Specification of the rollable OTFT-driven OLED display
Source: Sony
To create the flexible panel, Sony developed OTFTs with an original organic semiconductor material (a PXX derivative) with eight times the current modulation of conventional OTFTs. This was achieved with the development of integration technologies of OTFTs and OLEDs on an ultra-thin 20 μm thick flexible substrate.
In addition, all insulators in the integration circuit were replaced with soft organic insulators. A flexible on-panel gate-driver circuit with OTFTs was able to get rid of conventional rigid driver IC chips which interfered with the roll up of the display.
The company stated that the improved OTFT achieved the world's highest resolution OTFT-driven OLED display.
Sony will continue with the development of the solution / print based process for manufacturing display devices from organic materials that are easily dissolved in common solvents. "This process requires fewer steps, and consumes materials and energy more efficiently - thus has a smaller environmental footprint - compared to the conventional high temperature vacuum semiconductor process which use inorganic, silicon materials," they said.
For more attend: Printed Electronics USA 2010.
Reference: Sony
