Graphene to be used to create cheap, flexible printed cameras

Researchers at University of Cambridge to lead development of technology

Researchers at Cambridge University are to use graphene and two-dimensional materials to make printed and flexible “artificial eyes”.

The goal of the 18-month project, funded by the National Science Foundation of China, is to design and develop cheap printed flexible cameras, or photodectors, based on graphene and 2D crystal-based ink, which can be printed or stamped on plastic or paper and integrated with a range of commercial electronics.

Dr Felice Torrisi, lead researcher on the project from Cambridge University's Graphene Centre, said: “For example, it might eventually be possible to embed these printed, flexible optoelectronic devices into clothes, packaging, wall papers, posters, touch screens or even buildings.

“Everybody with a printer at home could be able to print their own “artificial eye” and physically stick it to a flexible mobile phone,” he added.

In 2012, he and two colleagues at the Cambridge Graphene Centre invented a graphene-based ink that conducts electricity and can be printed by a standard inkjet printer. The ink “enables cost-effective, printed electronics on plastic.”

The team has since been researching how to formulate a set of inks based on various 2D crystals for printed electronics, including hexagonal Boron Nitride, Molybdenum Disulfide, and Tungsten Disulfide. These crystals can be made optically active once reduced to a single 2D layer, with “a fast response time and excellent stability.”

The latest research project aims to use graphene and 2D crystal-based ink to overcome problems with the current generation of flexible photoactive materials, which are based on organic polymers.

These include slow response times of a few milliseconds, which is too slow for photodetection. Unlike graphene, organic polymers also suffer from chemical instability at room conditions, thus requiring extra protective layers or special handling of the printed devices, leading to an increase in cost.

Torrisi said: “The optical response of the printed 2D crystal inks, combined with their flexibility on plastic substrate and environmental capability, are key benefits to improving flexible optoelectronics.

“This will create an entirely new set of tools for printable electronics with conductive, semiconducting and insulating properties, with a faster response time, outperforming the current organic semiconducting inks, enabling printed, flexible photodetectors and possibly paving the way for printed flexible photo-cameras.”