Researchers at the University of Nottingham claim to have cracked the secret to 3D printing novel electronic devices capable of useful work like converting light into electricity — by putting graphene and other 2D material flakes into an inkjet printer.
"By linking together fundamental concepts in quantum physics with state-of-the art-engineering, we have shown how complex devices for controlling electricity and light can be made by printing layers of material that are just a few atoms thick but centimetres across," co-author Professor Mark Fromhold explains of his team's paper. "According to the laws of quantum mechanics, in which the electrons act as waves rather than particles, we found electrons in 2D materials travel along complex trajectories between multiple flakes. It appears as if the electrons hop from one flake to another like a frog hopping between overlapping lily pads on the surface of a pond.”
"While 2D layers and devices have been 3D-printed before," adds co-author Dr. Lyudmila Turyanska, "this is the first time anyone has identified how electrons move through them and demonstrated potential uses for the combined, printed layers. Our results could lead to diverse applications for inkjet‐printed graphene‐polymer composites and a range of other 2D materials. The findings could be employed to make a new generation of functional optoelectronic devices; for example, large and efficient solar cells; wearable, flexible electronics that are powered by sunlight or the motion of the wearer; perhaps even printed computers."
The team's work concentrated on using an inkjet printing system to build up layers of a 2D material into 3D structures — and in modeling the quantum mechanics of how electrons move through the layers, as a key part of understanding how the printed devices operate and can be modified and improved in the future. The system proposes a technique in which inkjet-based 3D printing can replace current hand-assembly approaches for assembling "sandwiches" of graphene and other two-dimensional materials.
The team's work has been published in the journal Advanced Functional Materials under open-access terms.