Characterizations of three-dimensional deployment behavior of shape memory polymer composite antennas

Deployable antennas have good transportability due to their small volume when folded. A launching vehicle is launched with a folded antenna, after which the antenna can conduct its mission after unfolded in space. Existing deployable antennas have some drawbacks such as heavy weight and small deformability. Shape memory polymers (SMPs), smart materials which have ability to recover their original shape from deformed shape by external stimulus such as heating, can be used to overcome these disadvantages. Deployable antennas made up of SMPs have advantages including light weight, large deformability, good processability, and self-transformation capability without any power device. However, they have not enough mechanical properties for aerospace application, promoting various researches to enhance their mechanical property, e.g., by introducing fillers into SMPs. In this research, multi-walled carbon nanotubes (MWCNTs) were used to improve the mechanical properties of SMP. The mechanical, thermal and shape memory properties of CNT/SMP composites were characterized. Compared to the neat SMP, the mechanical properties of the CNT/SMP composites, in particular strength and stiffness were improved. In order to investigate the feasibility of the CNT/SMP composites in aerospace, a miniature of circular reflector was fabricated. The deployment test of the reflector was conducted in a heating chamber. The deployment behaviour of the reflector was characterized using a 3D shape descriptor which is a computational tool used to analyse the 3D shape information. As a result of the deployment test, the folding efficiency and the shape memory performance was evaluated focusing on the effect of CNTs on the shape memory polymers.