Graphene in the aerospace industry
Graphene’s properties – as discussed in an earlier article – make it a highly viable material in the aerospace industry. For example, it has the potential to reduce the overall weight of the aircraft due to its low density and it can increase the strength of materials due to its mechanical properties. These features could contribute towards a reduction in an aircraft’s fuel consumption and hence improve the sustainability of air transport. This article explores some of graphene’s potential uses in the aerospace industry alongside its limitations and challenges.
Benefits of using graphene and potential uses
Lower manufacturing costs
Graphene’s extraordinary thermal properties can be exploited in the production of CFRP (Carbon Fibre Reinforced Polymers) materials . These materials are composed of numerous carbon fibres locked into place with a plastic resin, and they have a high strength-to-weight ratio as compared with metals. These lightweight materials – as illustrated in Figure 1 – are used widely in the aerospace industry. Graphene can reduce the cure times for resin-based materials and hence lower the overall manufacturing costs .
Figure 1. An example of a Carbon Fibre Reinforced Polymer 
Improve fuel tanks
Aircraft fuel tank systems, as showcased in Figure 2, require a filter element. Graphene oxide membranes can remove water contamination from fuel tanks . This is important to improve the overall fuel efficiency of the aircraft. Moreover, printed graphene sensors can replace the metal sensors to detect the fuel level . This is particularly beneficial as graphene – unlike metals – does not rust in humid conditions. Graphene also has good fire retardancy properties and showcases great chemical barrier resistance, which can be exploited to improve the safety of the fuel tanks . This can also be used to create an experimental propulsion system that can improve the sustainability of the aircrafts.
Figure 2. An aircraft fuel tank system 
Advanced flight deck avionics
Graphene on a polymer substrate can be used as a flexible transparent conductor, which can then be combined with organic electronics to provide a new generation of head-up displays, directly integrated into the windscreen of an aircraft , as illustrated in Figure 3. This can also pave the way for further advancements in technology and possibly also assist in developing driverless cars.
Figure 3. A futuristic cockpit 
Graphene wings - preventing heat spots and electromagnetic interference shielding
Graphene can be used within the wings of the aircraft to improve various aspects of the flight. Primarily, graphene’s thermal properties can be manipulated to minimise the heat spots on the wings. These heat spreaders could be formed from compressed graphene sheets or graphene compounds – i.e. graphene added to a polymer or rubber . This is critical for the safety of the aircraft as lightning strikes can create heat spots which could compromise the structure of the wing. Moreover, graphene’s electrical conductivity could help carry the electric currents from lightning strike safely away from the electronic circuits in the wings . As such, graphene’s conductive properties could be harnessed to create an electrically conductive framework that resists electromagnetic impulses. Due to its unique optical transitions, graphene in aircraft wings can also be used to shield the aircrafts from electromagnetic interference . It will make the future aircrafts more secure. Overall, using graphene in the wings of the aircrafts can have a multitude of benefits which will ultimately make air travel safer.
Challenges of using graphene in the aerospace sector
In aerospace engineering, it is critical to actually predict the impact that the introduction of graphene will have on the wider aircraft. Specifically, it is important to understand and simulate the graphene performance enhancements during the design stages in order to optimise the gain . However, it is incredibly difficult to create models which can accurately simulate this. Therefore, one of the key challenges for graphene in the aerospace sector remains the uncertainty around what the material can truly achieve. As graphene penetrates other markets and industries – such as biomedical engineering – it will be possible to draw broad parallels between different utilities to construct some computer models.
Extreme weather conditions
Aircrafts experience a huge range of temperatures –20 °C to -40 °C – between take-off and landing . As such, graphene composites would need to withstand extreme conditions – ranging from water freezing to water condensing inside the fuselage . This could potentially have an adverse impact on graphene’s conductive properties. Consequently, there will need to be more focused research to evaluate whether graphene-based materials can indeed function as necessary in these extreme conditions.
Perhaps the biggest challenge faced by the aerospace industry is the industrialisation of graphene . Although it is easier to observe the effects of using graphene on a small scale, it is more difficult to scale this up on a global basis. With the rise of globalisation and the need for standardisation, graphene must overcome this hurdle to have a seismic impact on the aerospace industry. Specifically, graphene production methods must be developed further to support the specialised production of graphene as required for the niche applications within the aerospace industry. This challenge will be discussed further in the next section.
Graphene must be integrated within the existing technologies to improve them. This could prove to be challenging in some instances. For example, to use graphene in the wings of the aircraft, it must be integrated within the wing. Although this might not seem as challenging considering the size of graphene, it will be important to account for the aeroelastic tailoring . This refers to the shape of the wing as based on the material that it is made out of . As graphene is extremely light, adding it to the wings could have a considerable impact on the shape of the wings – which would make it challenging to integrate the graphene-based technologies within existing aircrafts. Moreover, graphene in itself would not create a breakthrough in the aerospace industry. As such, further research would need to be conducted to discover technologies that complement and further enhance the properties of graphene to observe a true aerospace engineering revolution.