FlexiLEDs with printed graphene based thermal management

Extremely small flakes of Graphene have been made into printing inks which can pattern thin plastic sheets as well as paper. The flakes are derived in an industrial process from high quality graphite particles in a process known as exfoliation. After the printing process the graphene flakes are organised in a loose arrangement and the contact area between graphene flakes is small. We are developing a conversion process to compress selected areas of the printed graphene regions to enhance heat transfer properties and at the same time make it more efficient when transferring electrical current for integrated electronic and optoelectronic components. Our first demonstration will be flexible sheets of micro LEDs and will lead to completely new and novel formats of solid state lighting and indicator devices. Further development may allow everyday packages to be smart and able to capture data which becomes incorporated in to the internet of things. Other applications would be wearable displays, point of care diagnostic strips, touch devices for light weight vehicles as examples.

UK Industries have the infrastructure and skilled staff to commercialise the proposed research. Applications include:

Food, fast-moving consumer goods (FMCG) and other plastic packaging - Intelligent and smart labels which integrate LEDs, wireless comms, sensors. Nano Products Ltd a partner in the project would be a significant global manufacturer of such devices.

Aerospace - intelligent switches and control panels where space is at a premium. Light weight intelligent lighting for the cabin on commercial aircraft.

Automotive - Low profile lights integrated into bodyshell panels as well as intelligent dashboards and facia in vehicles. Architectural design, building and construction - New thin intelligent flexible lighting formats which interact with the environment including people.

Medical device companies which require void free and recess free surfaces to ease cleaning and reduce harbouring pathogens but require a Human Machine Interface will benefit from the ability to injection mould switches, LED indicators, wireless comms and inductive power transmission coils.

Smart disposable woundcare management devices which use light to control the release of drugs or use discrete or printed sensors to monitor wound state.

Diagnostics - Disposable point of care diagnostics which use functionalised high surface area graphene electrodes to measure human and animal health as well as industrial and environmental applications.

Low cost disposable objects which will make up the Internet of Things; e.g. Solid State lighting with sensors and wireless comms to the cloud via the internet.

Displays - A wide range of flexible information displays. From flexible daylight readable armband displays to augmented reality displays which fuse basic symbology over the wearer's field of view. Others include flexible backlighting for flexible signage

Fashion and design of clothing which integrate LEDs onto breathable linings such as Gore Tex

For the companies involved in the project - Nano Products will formulate, print and compress graphene for new customers. It would adopt micro Transfer printing as an enabling technology for device assembly. Thomas Swan and Co. Ltd would grow its Elicarb Graphene business. Plessey Semiconductors would extend is global lead as a supplier of thin film GaN LEDs. All of the above will benefit from increased revenues, new products and the potential to innovate a vast number of new solutions for customers. Regional employment and the quality of employment would increase

The benefits to public individuals are in health, welbeing and quality of life. For the UK the product innovations can be manufactured in the UK without excessive investment. The move to more sustainable materials such as bioplastics, elimination of wirebonds and conductive adhesives and reduction of metals used in plastic electronics will reduce the environmental impact and help create a robust supply chain.

Transfer from inefficient fluorescent and incandescent technology to efficient LEDs has progressed well as such this research will help to maintain the security of energy supply by maintaining the efficiency of LEDs when used in Flexible devices.