## 3 Aerospace Engineering Applications
### Other Applications to Aerospace

Table 4: Investigation details of SMA applications in morphing wing. 777-300 ER [113; 114]. It was proved that the proposed device had a great effectiveness in noise reduction during take-off by maximizing the deflection of the chevron and also had an effectiveness in increase in the cruise efficiency by minimizing the deflection of the chevron during the remainder of the flight. [PERSON] et al. proposed artificial folding wing models mimicking the hindwing mechanism of a beetle using SMA wire actuators [115]. It was confirmed that the proposed artificial hind wing had appropriate flexibility when it was flapped at a wing beat frequency of 9 Hz at a flapping angle of 120\({}^{\circ}\) without folding back during the flapping motion. The photographs for the demonstration of the foldable wing are presented in Figure 9. [PERSON] et al. introduced a compressed mesh washer pyroshock isolator with the pseudoelastic characteristics of SMA wire [116]. After manufacturing of the compressed mesh washer isolators, the pyroshock isolation performances were evaluated experimentally. It was confirmed that the isolation capability can be adjustable by adjusting the pre-compressive displacement of the compressed mesh washer isolator. [PERSON] et al. developed a micro-vibration isolator including SMA-based mesh washer for the spaceborne cryocooler [117]. The undesirable micro-vibration disturbances induced by on-orbit operation of a spaceborne cryocooler is one of the main reasons for the deterioration of the image quality obtained from high-resolution observation satellites. Then, the micro-vibration disturbances caused by operation of the cryocooler must be effectively isolated. The mechanical characteristics of the isolator-integrated cryocooler assembly were identified via static and free vibration tests. It was experimentally demonstrated that the proposed isolator design was effective for the system under requirement temperature limits. [PERSON] et al. proposed a new concept of a releasing system using an SMA actuator for aerospace engineering [118]. Usually, the releasing and deployment maneuvers performed during launching of space satellites are executed by utilizing loads of pyrotechnics. In order to reduce high shock and vibrations and to avoid the pollution of functional instruments due to dust and gas release during explosion, they tried to replace pyrotechnic loads by others not requiring explosives. The performance of a non-explosive actuator device to cause controlled fracture of a notched bolt was analyzed using the mechanical stress generated during reverse deformation of a mechanically constrained SMA actuator. Since the late 2010s, research on self-deploying solar sail systems using SMA has been actively reported. [PERSON] and Tata developed a self-deploying solar sail system using SMA wires and manufactured a small-scale prototype for the experimental evaluation [119]. In the prototype, three different structural configurations were considered and two different SMA wires were used for self-deployment of the solar sail. [PERSON] et al. designed and manufactured a miniaturized self-deploying system based on SMA wires integrated with a carbon fiber loom [120]. In particular, they focused on the relationship between surface-weight ratio and the deployment of the solar sail. After experimental tests with a compact prototype solar sail, it was confirmed that high surface-weight ratio values can be obtained by using light parts such as prepreg looms and rolled wires as active elements. SMA-based self-deploying solar sails manufactured by Costanza and Tata and commercial pure aluminum thin sheets with thin adhesive Kapton were used to simulate the sail. [121]. In the laboratory experiment, the effects of different heating techniques and different pressure situations on the activation time were intensively considered. [PERSON] et al.