Most of human experience in spaceflight has been in Low Earth Orbit (LEO): only about 0.5% of total human spaceflight has occurred beyond LEO, during the Apollo lunar missions. Human exploration missions beyond near Earth orbit cannot occur without a validated approach to addressing astronaut health risks due to radiation. This requires characterization of the space radiation environment and the experimental validation of radiation protection methodologies. The deep-space radiation environment is reasonably characterized, but radiation protection materials for human habitats and spacesuits have not been fully developed and characterized. Advanced materials for spacesuits and surface vehicles can enhance crew safety and will be an essential component to be able to work and live in this airless environment safely. These new materials can provide protection to vulnerable organs in humans and engineering systems for critical operability. This project will address how to design, manufacture and incorporate new materials with synergistic capabilities (in particular, polyethylene polymer composites containing graphene and regolith particles) in situ, using the Additive Manufacturing (AM) process.
Among the Additive Manufacturing (AM) techniques, Fusion Deposition Modeling (FDM) is one of the most popular 3D-printing methods. Thanks to its flexibility in terms of materials choice, to its relatively low cost and to the good quality of the produced parts, has recently been investigated for the manufacturing of multifunctional nanocomposites [1-3]. However, most of recent research has focused on the 3D-printing of ABS (acrylonitrile butadiene styren) and PLA (polylactic acid) nanocomposites due to the low melting temperature, the satisfactory mechanical properties and the well-established process parameters of these thermoplastic polymers [4-6]. In fact, issues related to the 3D-printing of polyethylene (e.g. adhesion and warping problems) have drawn the researchers towards the use of other materials [4-7]. This project will focus on the optimization of 3D-printing process parameters for the fabrication of polyethylene-based materials, such as filament extrusion temperature and velocity, as well as particles (carbon nanoparticles and regolith particles) weight percentages. In addition, to the best of our knowledge, neither numerical nor experimental approaches have yet been established for the study of the AM process of polyethylene-based composites and nanocomposites. For these reasons, this research is envisioned to bring significant contributions in the field of AM of multifunctional materials for which the electrical, thermal, mechanical and radiation shielding properties will be numerically and experimentally validated. There is lack of knowledge on the radiation shielding properties of 3D-printed polyethylene parts as well as on the shielding effectiveness of polyethylene loaded with regolith simulant and/or carbon nanoparticles. In fact, NASA has only recently validated the use of additive manufacturing in space environment [8], and therefore, the multifunctional properties of 3D-printed polyethylene components still need to be validated.
[1] T. A. Campbell, O. S. Ivanova. 3D printing of multifunctional nanocomposites. Nanotoday, 8(2): 119-120, 2013.
[2] Wang, X., Jiang, M., Zhou, Z., Gou, J., & Hui, D. 3D printing of polymer matrix composites: A review and prospective. Composites Part B: Engineering, 110: 442-458, 2017
[3] Gnanasekaran, K., Heijmans, T., Van Bennekom, S., Woldhuis, H., Wijnia, S., de With, G., & Friedrich, H. 3D printing of CNT-and graphene-based conductive polymer nanocomposites by fused deposition modeling. Applied materials today, 9: 21-28, 2017.
[4] Prashantha, K., & Roger, F. Multifunctional properties of 3D printed poly (lactic acid)/graphene nanocomposites by fused deposition modeling. Journal of Macromolecular Science, Part A, 54(1): 24-29, 2017. (PLA)
[5] Yamamoto, B. E., Trimble, A. Z., Minei, B., & Ghasemi Nejhad, M. N. Development of multifunctional nanocomposites with 3-D printing additive manufacturing and low graphene loading. Journal of Thermoplastic Composite Materials, 32(3): 383-408, 2019. (ABS)
[6] Guo, S. Z., Yang, X., Heuzey, M. C., & Therriault, D. 3D printing of a multifunctional nanocomposite helical liquid sensor. Nanoscale, 7(15): 6451-6456, 2015. (PLA)
[7] Wang, X., Jiang, M., Zhou, Z., Gou, J., & Hui, D. 3D printing of polymer matrix composites: A review and prospective. Composites Part B: Engineering, 110: 442-458, 2017.
[8] Prater, T. J., Werkheiser, N. J., & Ledbetter III, F. E. (2018). Summary Report on Phase I and Phase II Results From the 3D Printing in Zero-G Technology Demonstration Mission. Volume II.