Flexible Electronics
Work Package 8, Flexible Electronics (WP8), is devoted to what the Graphene Flagship describes as the next ubiquitous platform for the electronics industry. Graphene – a thin, flexible, ultra-strong and highly conductive film – is an obvious choice for flexible electronics. This 2d material will enable a wide range of applications, in a way similar and complementary to silicon technology. Work package leader is Stefano Borini of Nokia Technologies in Cambridge, and deputy Sebastiano Ravesi of STMicroelectronics in Catania.
Flexible materials and components
WP8 has over recent months been making steady progress in the development and benchmarking of graphene and related materials on flexible substrates. Its members are also looking at the realisation and testing of flexible components, including first steps in system integration.
Functional graphene inks have been formulated and printed onto plastic substrates, for both circuit tracks and sensing elements, and the inks show a promising combination of performance and mechanical stability. Different types of printed sensors, including strain gauges and infrared detectors, have been demonstrated. All have competitive figures of merit, with a gauge factor of 17 in the case of flexible strain sensors.
Processes for depositing large-area CVD graphene on plastics have been developed, and these have been optimised for a number of applications. By controlled doping of graphene on plastics, for example, WP8 researchers have produced a transparent conductor with superior mechanical stability under bending. At the wafer scale, they have also manufactured graphene field-effect sensors with integrated microfluidics.
Flexible wireless devices
Radio-frequency components are another focus of WP8 activity, and RF transistors with a maximum frequency of 13 GHz have been produced on the polyimide film Kapton. Such devices retain their functionality under static bending, and display long-term stability when subject to fatigue cycles.
When it comes to flexible RF antennas, WP8 researchers have demonstrated printed graphene dipole antennas with decent performance in UHF and >2 GHz frequency ranges. Again in the wireless domain, first prototypes of flexible Near-Field Communication (NFC) antennas based on graphene paper have been built. These could provide a very competitive solution for flexible RFID tags.
Platform integration
WP8 researchers have designed and realised an electronic platform for the integration of flexible components. The platform is an essential enabler for the fast prototyping of flexible components and their gradual integration into functional flexible systems. WP8 is now working on flexible demonstrators that combine several technologies based graphene and related materials. A first prototype of a wearable device based on graphene sensors has been designed, and should be delivered by the end of the Graphene Flagship's ramp-up phase in April 2016.
WP8 leader Stefano Borini: "Materials experts are working together with components manufacturers and system integrators, delivering flexible demonstrators and prototypes with potential impact in several emerging fields such as wearables and the Internet of Things."