In Germany, Dr Manuela Garnica Alonso peers into a massive machine of shining steel that sprouts wires, tubes, clusters of portholes, aluminium foil and industrial bolts.
The inside of the chamber is less than a trillionth of the air pressure in the surrounding lab. It also contains a heater that can reach thousands of degrees and a microscope capable of imaging surfaces down to the level of the atom.
Dr Garnica’s goal is to create tiny but completely perfect materials in just two dimensions.
Sometimes she simply wants to prove that they can, indeed, be coaxed into existence. Other times the goal is to thoroughly understand their physics, and sometimes she has also ‘decorated’ them with atoms and molecules, just to see what happens.
She is at the leading edge of an explosion in making 2D materials since a one-atom-thick layer of carbon known as graphene was first isolated in 2004 by pulling sticky tape across the surface of a pencil.
In a recent paper published in Nature Chemistry, Dr Garnica, who is based at the Technical University of Munich, and her colleagues report that they have managed to make a new type of structure by fusing other organic molecules to the edges of graphene – a novel way of giving graphene interesting properties that could find applications in technology and medicine.
‘It is the first time that it’s been proved that graphene can be functionalised by this method,’ said Dr Garnica, who has been funded by the EU under the Marie Skłodowska-Curie Actions programme.
To make graphene, Dr Garnica heats a rod of graphite to thousands of degrees until a few atoms of carbon gently lift away and lay themselves, in a single layer, on a crystal of silver.
She also wants to make a 2D layer of silicon carbide, highly anticipated amongst theorists as a semiconductor that could rival silicon, the material that forms the basis for the electronic circuits we use today.
She is simultaneously vaporising graphite and a wafer of silicon, in the hope that their atoms will nestle together into a honeycomb lattice atop another crystal of silver.
The goal is to thoroughly understand 2D materials at an atomic level. That’s because, since graphene was first discovered in Manchester, UK, 2D layered materials are giving engineers the tools they need to create the highly efficient and flexible devices needed for a low-carbon world.
‘It is just one of hundreds, if not thousands of layered materials,’ explained Professor Jonathan Coleman at Trinity College Dublin, Ireland, who has now created 25 different 2D materials – and he’s still going.
He’s at the other end of the scale, making 2D materials using the laboratory equivalent of a kitchen blender.
Prof. Coleman perfected his technique on graphene, dissolving graphite in soapy water and then blending it.
‘Nanoscience doesn’t have to be complicated, it doesn’t have to be high tech.’
Prof. Jonathan Coleman, Trinity College Dublin, Ireland
The blades slice through the liquid with a shear energy that slides graphite layers apart, and the soapy water swiftly coats each flake, preventing them from clumping back together.
Boron nitride, an effective insulator, was next. ‘It’s the simplest after graphene,’ said Prof. Coleman.
Soon after came molybdenum disulphide, which as it turns out can hold three to four times as much electric charge as the graphite that is traditionally used in lithium-ion batteries. He has also created a 2D version of nickel hydroxide, a catalyst which could improve the quality of fuel cells, which make electricity from hydrogen and oxygen.
To his surprise, Prof. Coleman’s blender technique has also managed to make phosphorene – one of the potential high-flyers of the 2D world because, like silicon carbide, it promises to be a semiconductor to rival silicon.
Although it is very unstable, he found that if he adds certain liquids to the mix they will protect the sheets of phosphorene from chemicals that might react with it, leading to a substance that might be useful in batteries and gas sensors.
‘Nanoscience doesn’t have to be complicated, it doesn’t have to be high tech,’ said Prof. Coleman, who has been funded by the EU’s European Research Council.
‘It can be quite simple, and that’s actually really important.’
Prof. Coleman discussing graphene at TEDxBrussels.
There are about 1,500 potentially active volcanoes worldwide and about 50 eruptions occur each year. But it’s still difficult to predict when and how these eruptions will happen or how they’ll unfold. Now, new insight into the physical processes inside volcanoes are giving scientists a better understanding of their behaviour, which could help protect the 1 billion people who live close to volcanoes.
Artificial intelligence (AI) used by governments and the corporate sector to detect and extinguish online extreme speech often misses important cultural nuance, but bringing in independent factcheckers as intermediaries could help step up the fight against online vitriol, according to Sahana Udupa, professor of media anthropology at Ludwig Maximilian University of Munich, Germany.
As the first coronavirus vaccines started to be rolled out at the end of a tumultuous 2020, UK officials unexpectedly endorsed stretching the gap between the first and second vaccine dose by up to three months – an approach also considered by other countries.
Pragmatic or dangerous – what do the experts say?
Better predictions of volcano behaviour could protect people and infrastructure.
Dr Kate Rychert studies ocean plate structures.