Venue: University of Manchester, United Kingdom
Date / Time: 17 July 2022, 3 - 5pm
Today, I visited the National Graphene Institute (NGI) with three of my father’s friends and Nobel prize winner Konstantin Novoselov. The experience, overall, was mind-blowing and astonishing. The NGI is world’s greatest and biggest research and development centre for the synthesis, production and use of graphene, with its layout planned by Mr Novoselov. I was amazed by the sheer size of the building and the number of research rooms that are in it. One of the person who went with us is studying chemical engineering in his second year of university, who is aiming for his master degree.
Konstantin showed us around the institution, introducing to us what equipments there are and the experiments carried out in each laboratory, opening my eyes to the biggest and most advanced research labs of graphene.
Next, I will introduce some of the equipment used. Firstly, I will explore the set-up used to produce the quantum hall effect of graphene, which is stimulated in low temperatures and strong magnetic fields.
The quantum hall effect in graphene happens when graphene is subjected to a strong and perpendicular magnetic field to its surfact up to 10 Tesla, in low temperatures such as 300 milliKelvin, equivilant to negative 272 degrees celcius. It is very fascinating and mind-blowing to me how this can be generated using a huge cylinder. In addition, these equipments are all in an enclosed dark room away from the rest of the laboratory because these equipments are very sensitive to signals outside.
Above is the CVD process in order to produce graphene. I was told by Konstantin that the coloured vapour in the connected glass tube is a catalyst such as nickel or copper. Furthermore, Konstantin said that there are two ways to produce graphene, one is by the top-down method. In this method, graphite is stripped off its layers one by one, a process called mechanical exfoliation simply converts graphite to graphene. Another more efficient method is CVD. It is to form dissociate carbon atoms from the thermal decomposition of hydrocarbons. Firstly, the hydrogen atoms are separated from carbon ones. Then, the carbon is then heated at around 1000 degree celcius with a copper catalyst to produce graphene sheets.
Another interesting equipment I came across is the atomic force microscope. I was told that it is well suited for investigating the nanoscale properties of nanocomposite materials. Essentially, it is an imaging technique that measures the geometric properties of a surface with picometer (10^-12) height resolution. Moreover, many material properties such as electrical, magnetic and nanomechanical properties may be varied for the sample being tested.
The FIB SEM is a dual-beam instrument used to fabricate, measure and characterize nano-devices. Furthermore, the ion beam can engrave structure in graphene, and be used to deposit materials precisely. To accurately image the device, the high resolution electron column is used. Even more suprisingly, the temperature in this room is controlled to within 0.1 degree celcius with its own air supply.
This is an area where optical lithography takes place. The structures of the samples is determined by complex patterns are drawn in with high intensity UV light, which is similar to what is used in modern electronic industry. The yellow appearance is a result of UV light being blocked from the room because it may damage the process.
The above image is just one of the many laser and optics investigation labs. I was amazed at how such a complex system is incoperated into such a limited amount of space, and the complexibility of the experiments conducted.
A sample is placed at the bottom of the set-up similar to a cylinderical shape called Chrysler. This is similar to what I observed in NUS, but the system here is bigger and seems more complex to operate than the ones back in Singapore. Chrysler is able to lower the temperature of the set-up drastically, and then test the sample’s electrical properties and to monitor the performance of electrical components under extremely low temperatures.
However, the only disappointing aspect is that I did not get to go into the laboratory that requires us to wear a thick lab coat and shoes. This is because there is ultra-high vacuum (UHV) equipments inside the lab, and protection must be worn to keep the workplace clean and it is very essential that it is kept clean with no contamination, part of the reason why it is isolated by glass doors from the rest of the building.
As you can see above, this area contains the 2D material nanofabrication process. In an ultra-high vacuum environment (UHV), this provides tools to produce and study the intermolecular forces that is acting on heterostructures. This equipment is also able to create devices with interfaces free from atmospheric contamination. As stated in the diagram, scientists have to “stack 2D materials with positioning accuracy greater than 1 μm while maintaining temperature up to 1000°C” Therefore, I was awe-struck by the enormous amount of precision and accuracy required to stack different 2-dimensional materials on top of one another. In addition, I also realized the huge amount of skill and expertise of the workers there, and it motivates me to work harder now to achieve what I want to study later in life.
This is the world’s first multi-chamber cluster tool to produce and study heterostructures in ultra-high vacuum. The UHV system allows for the stacking of materials on top of one another to make artificial solids, thus allowing for the customization of the materials’ chemical and electrical properties. This chamber also allow scientists to isolate atomically thin materials in UHV, allowing them to create pristine interfaces which is free from atmospheric contamination. Additionally, there is also the capability to use optical microscopy and spectroscopy to identify the thickness of exfoliating crystals, which can then be assembled in chosen sequences to produce “van der Waals heterostructures”, which are designer solids with customizable electronics and optical properties.
A UHV environment is vital for producing high quality one atom thick films of metal and insulators. The deposition chamber combines magnetron sputtering and electron beam-assisted deposition to produce electrical contacts directly onto the pristine interfaces of 2D heterostructures devices. When removed from the UHV chamber, these contacts can be used to study the electrical properties of a device.
Konstantin told us that this microscope is used to investigate interactions across surfaces. This equipment can measure frictional properties, determine conductivity across a sample with nanometre resolution. The modes can be used to investigate graphene composites to design improved materials, analyse samples in a liquid environment at a range of temperatures, and perform electrochemical measurements. It is now used for scientists to look at how batteries made from 2D materials change as they are charged and discharged, allowing for the discovery of when the structure starts to fail. Therefore, this allows for the design of longer lasting batteries.
The most exciting part is getting to see the basement, where all the behind-the-scenes of the laboratories take place.
It is quite interesting to see some of the large pipes and thick exhaust tubes that runs throughout the area. There is a mix of heavy and light equipments, I am assuming that this is the archive area for the chemicals and equipment used upstairs. I could even feel the vibration of the floor as I walked on it. Interestingly, I learnt that these behind-the-scenes equipments are housed on an entirely different building which is connected to the main building, so that the main building does not have the vibration of the floor.
Next, I entered the largest lift I had ever seen or taken to the ground floor. It does not look very big in the picture but I swear, it looks humongous!! I was told that this lift is used to display cars, and I am obviously not surprised because this lift is so much bigger than a car.
All in all, I love this opportunity to come here and take a look at the greatest laboratory in the world for leading research on graphene. This definitely stimulated my interest and curiosity in the subject of material science and I could not wait for next time when I go to this place again!
