The aerospace industry is continually involved with new technologies occurring almost yearly. One such technology engineers are working on is carbon nanotubes (CNTs).
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CNTs are molecular structures formed of rolled graphene sheets that form single-walled or multi-walled concentrically linked nanotubes. CNTs also offer distinctive physical features, making them fascinating for innovative material synthesis in the aerospace sector.
The Use of Nanotubes in Aerospace
The structure of a modern aircraft consists of various composite materials assembled into a multi-layered pastry-like structure.
Leading aircraft manufacturers construct their passenger jets using composite materials, such as plastic reinforced with carbon fiber. The advanced composite materials offer exceptional durability and significantly reduce the airplane's overall weight compared to traditional aluminum aircraft.
While most advanced composite materials offer extraordinary properties, they are vulnerable. Unlike metal, which can endure significant impacts before splitting, composites with several layers may be damaged by minimal impact.
Addressing the Problems of Composites Using Nanotubes
Engineers have found a method for producing aerospace-grade composites that use CNTs and address the limitations of conventional composites. The resultant material is much more durable and offers better damage resistance when compared to previous composites. Engineers devised an alternative that involves incorporating CNTs, which are atom-thin carbon coils with tremendous strength.
The researchers developed a technique for embedding small "forests" of CNTs into a polymer matrix similar to glue. Scientists then sandwiched this glue-like structure between carbon fiber layers. The tubes, which looked like vertically oriented threads, found their way into the spaces between the composite layers, acting as a foundation to hold them together firmly. This novel technique strengthens the material's structural integrity, improving its efficiency and longevity in aeronautical applications (Guzman et al. 2016).
Applications of Carbon Nanotubes in Satellites
CNT's electrical conductivity has practical uses in antenna design, increasing performance by twenty times above conventional antennas. Furthermore, CNTs conductivity allows for excellent electromagnetic radiation protection. CNTs are particularly important in improving battery technology since their use as electrode materials enhance energy density while coping with high temperatures (Prasad et al., 2018).
CNTs are valuable additive materials, combining with other elements to build space-ready structures. Their excellent thermal conductivity makes them perfect for producing materials that efficiently absorb light. This feature reduces stray light and is also used as a solar panel coating, substantially improving the solar panel's light-absorbing ability (Gohardani et al., 2018).
The thruster, a vital component of satellite propulsion, may benefit considerably from CNT's field emission capability. Nanotubes increase the satellite's overall efficiency by boosting each component's performance (Prasad et al., 2018).
Challenges and Limitations of Nanotubes
Impurities, non-uniform morphology and structure, hydrophobicity, and tendency to bundle up are just some of the hindrances to using CNTs in aerospace applications.
Numerous challenges obstruct the path toward fully integrating CNTs into the aerospace industry. While the potential of CNT implementation in the aerospace sector holds great promise, scientists have yet to fully realize the actual advantages of CNT implementation for aerospace utilization.
To fully capitalize on the benefits of CNTs in the commercial transport industry, overcoming challenges associated with CNT implementation in the aerospace sector is pertinent. These challenges encompass:
- The ability to produce CNT-based parts at a large-scale.
- Ensuring high-quality materials at a relatively low cost.
- Achieving optimized properties.
- Addressing concerns CNTs can have on the safety and health of humans.
- Developing recycling methods to minimize any environmental impact.
Future Prospects and Research Directions
NASA recently announced its plan for research in aerospace and aeronautics, stressing the development of much more secure aircraft that run efficiently and with lower environmental consequences. This research plan includes novel materials integrating nanotechnology, especially nanotubes, into aerospace applications.
NASA is studying CNTs extensively, believing they can play a big part in the evolution of the aerospace industry.
The Whipple shield, which is a shield designed to defend spacecraft/satellites from the impact of Micrometeoroid and Orbital Debris, is an intriguing CNT research area. When incorporated within the composite of a satellite, CNTs may help to improve its impact resistance significantly (Gohardani et al., 2018).
Thermal management of a spacecraft is a crucial aspect of its operations in space. Thermal management of any space system depends on effective heat transfer to keep devices within their operational range. Since CNTs are effective conductors of heat, they can be used to make composites for parts such as radiators, heat ducts, heaters, and insulation to improve the performance of thermal management systems (Gohardani et al., 2018).
The continually evolving dynamics within the nanotechnology sector indicate that it encompasses applications from various scientific disciplines. The future possibilities for revolutionary CNT-related ideas, mostly linked with aeronautical sciences, are, therefore, quite encouraging.
References and Further Reading
Chu, J. (2020). A new approach to making airplane parts, minus the massive infrastructure. [Online] MIT News. Available at: https://news.mit.edu/2020/carbon-nanotubes-making-airplane-aerospace-parts-1013
Berger, M. (2021). Carbon nanotubes – what they are, how they are made, what they are used for. [Online] Nano Werk. Available at: https://www.nanowerk.com/nanotechnology/introduction/introduction_to_nanotechnology_22.php
Prasad, A., Godwin, A., (2018). Carbon Nanotubes: Applications in Satellites. [Online] 42nd COSPAR Scientific Assembly. Available at: https://ui.adsabs.harvard.edu/abs/2018cosp...42E2725P/abstract
Gohardani, O., Elola, M. C., Elizetxea, C., (2014). Potential and prospective implementation of carbon nanotubes on next generation aircraft and space vehicles: A review of current and expected applications in aerospace sciences. Progress in Aerospace Sciences. doi.org/10.1016/j.paerosci.2014.05.002
Guzman, R., Hallander, P., Ydrefors, L., Nordin, P., Wardle, B. L., (2016). In-Plane Strength Enhancement of Laminated Composites via Aligned Carbon Nanotube Interlaminar Reinforcement. Composites Science and Technology. doi.org/10.1016/j.compscitech.2016.07.006