A flexible display that includes graphene in the active backplane that controls the pixels, has been demonstrated by a team from the Cambridge Graphene Centre at Cambridge University and Plastic Logic Ltd. (Cambridge, England).
Graphene-based conductors are more flexible than conventional alternatives, such as indium-tin oxide (ITO) and more transparent than metal films. As a result graphene may enable foldable electronics as well bring benefits from more efficient printed and roll-to-roll manufacturing.
The active-matrix backplane in this small-size monochrome prototype includes a solution-processed graphene electrode, which replaces the sputtered metal electrode layer within Plastic Logic’s conventional devices flexible display panels. The display is an active-matrix electrophoretic display, similar to the screens used in e-readers, except it is made on a flexible plastic substrate instead of glass.
Graphene is a two-dimensional material made up of sheets of carbon atoms. It is among the strongest, most lightweight and flexible materials known, and is expected to impact electronics due to its high mobility.
Graphene added to Plastic Logic's organic active-matrix display backplane could make for more flexible displays. Source: Cambridge Graphene Center.
The new 150 pixel per inch (150ppi) backplane was made at temperatures below 100 degrees C using Plastic Logic’s organic thin film transistor (OTFT) technology. The graphene electrode was deposited from solution and subsequently patterned with micron-scale features to complete the backplane.
For this prototype, the backplane was combined with an electrophoretic imaging film to create an ultra-low power and durable display. Future demonstrations may incorporate liquid crystal (LCD) and organic light emitting diodes (OLED) technology to achieve full colour and video functionality. Lightweight flexible active-matrix backplanes may also be used for sensors, with novel digital medical imaging and gesture recognition applications already in development.
"We are happy to see our collaboration with Plastic Logic resulting in the first graphene-based electrophoretic display exploiting graphene in its pixels' electronics,” said
"This is a significant step forward to enable fully wearable and flexible devices. This cements the Cambridge graphene-technology cluster and shows how an effective academic-industrial partnership is key to help move graphene from the lab to the factory floor," said Professor Andrea Ferrari, director of the Cambridge Graphene Centre, in a statement.
"The potential of graphene is well-known, but industrial process engineering is now required to transition graphene from laboratories to industry," said Indro Mukerjee, CEO of Plastic Logic, in the same statement.
Plastic Logic and the CGC have been awarded a grant from the UK Technology Strategy Board that is targeting the creation of a full-color, OLED-based display within 12 months.
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