Ahen Konstantin Novoselov and his colleague Andre Geim at the University of Manchester 18 years ago detached tiny flakes from a piece of graphite with a strip of adhesive tape and examined them more closely under the tunneling microscope, they not only made a groundbreaking discovery, they also heralded a new era of materials research. Because the two researchers held in their hands the first material whose atoms stretched out a two-dimensional perfect crystalline lattice in the form of a honeycomb pattern: graphene.
Although made up only of carbon atoms, the first samples of this substance already showed unusual physical properties that had not been known from any other material up to that point: stronger than steel, as flexible as rubber and as transparent as glass. Graphene is a better conductor of heat and electricity than copper wire. It can now even be transformed into a permanent magnet and a superconductor.
The “miracle material” seemed to be made for numerous high-tech applications, such as flexible displays, faster transistors and more sensitive sensors, better batteries and lighter vehicle and aircraft parts and much more. And the expectations were not disappointed, as Novoselov, who received the Nobel Prize in Physics together with Geim for this discovery in 2010, reported in his lecture in Lindau this year (click here for the video). Graphene has already replaced graphite as an anode material in many lithium-ion batteries and supercapacitors, and graphene is used for displays, touchscreens and thermal protection in some mobile phones. The 2D material is also installed under the bonnet in some car models to improve noise protection. Because of its optoelectronic properties, graphene is used, for example, as a light sensor in infrared cameras and night vision devices. According to Novoselov, the material has also proven to be an efficient filter material and can be used to desalinate seawater.
Konstantin Novoselov during his lecture in Lindau 2022: “Materials for the Future”
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Image: Julia Nimke / Lindau Nobel Laureate Meetings
The numerous applications are possible today because enormous advances have been made in graphene production. The special form of carbon can now be produced in large quantities using various processes, with the appropriate quality depending on the application. The way in which the material can be processed is also versatile. Graphene can now be printed on any surface like ink, for example to quickly and easily reproduce graphene components in a wide variety of shapes. Researchers working with Novoselov in Manchester have devised a process with which tiny RFID labels can be printed from graphene ink and produced in large numbers. RFID antennas are central to Industry 4.0: They allow objects to be identified and localized automatically and without contact using radio waves. The graphene labels are now being mass-produced by a British start-up in Manchester.
Intelligent materials show new functionalities
But graphene is far from the only known 2D material that Novoselov and his colleagues have their eyes on. Other elements are now known – including silicon, germanium and boron – as well as numerous semiconductor compounds such as molybdenum sulfide, tungsten selenide or boron nitride, from which thin layers with a honeycomb structure can also be produced. Novoselov estimates that several dozen other 2D compounds exist that exhibit a wide range of electrical and magnetic properties. These include chemically modified variants of graphene such as fluorographene or graphane, in which there is a hydrogen atom on each carbon atom.