# Application of Virtual Reality for Learning the Material Properties of Shape Memory Alloys
## 1 Introduction
Even if the school laboratory can afford to buy one, it is not easy for students to operate it correctly due to unfamiliarity with the operational procedures and the lack of theoretical or practical foundation. All these factors cause difficulty in understanding the SMA's crystal structures and material properties. Figure 1: A simplified manufacturing process of the SMA. Virtual reality (VR) is a computer-generated virtual environment to simulate the realistic or imagined world, where the 3D visual effect and interaction can be achieved by wearing a head-mounted display and button-operated handsets. It can also be called immersive multimedia because one can see and hear just like in the real situation and interact with others in the virtual world as if seeing each other face to face [13]. A virtual environment can satisfy the major requirements in the real experiments and training processes at a lower cost but without danger. VR is highly realistic and interactive, so it is suitable for applications in science and engineering education [14; 15; 16] to enhance the learning interest and motivation of students. VR has been applied in science education to help students understand microscopic phenomena not easy to observe with the naked eye [17; 18; 19]. In addition, VR can simulate the real-world situations by 3D animation, so it is suitable for presenting abstract concepts and experimental processes to enhance immersion and cognition and increase students' engagement in learning activities [20; 21; 22]. [PERSON], [PERSON], [PERSON], and [PERSON] [23] developed a virtual laboratory for synthesizing and analyzing nanogold particles using the virtual reality technology. A teaching experiment was conducted and the results showed that it can enhance students' learning effectiveness and motivation. [PERSON], [PERSON], and [PERSON] [24] reviewed a selection of the literature to compare the value of physical and virtual investigations and they offered recommendations for combining both approaches to strengthen science learning. [PERSON] and [PERSON] [25] compared the effectiveness of physical, virtual, and virtual-physical manipulatives on third-grade students' science achievement and conceptual understanding of evaporation and condensation. Their results revealed that using virtual preceding physical manipulatives and virtual manipulatives alone can enhance students' knowledge about evaporation and condensation better than using physical laboratory activities alone. Some studies highlight that the technology itself does not improve learning outcomes, but rather reflective thinking or learners' attitudes enable improvement to learning objectives [26; 27]. In this study, a teaching module is designed using the VR technology and the research results of SMAs for learning their properties, shaping, and restoration processes, as well as real-life applications (e.g., heat-driven motors and vascular stents) in an interactive and immersive way. The teaching module can be installed on mobile or head-mounted devices, enabling students to perform the virtual experiment of the SMA shaping and restoration. It can enhance the understanding of basic concepts through interactive operation and observation of structural changes with temperatures. A teaching experiment has been conducted to analyze students' learning effectiveness and attitudes after using the teaching module. The results can also be used for improving the system in the future. The rest of this paper is organized as follows: Section 2 introduces the SMA properties and applications. Section 3 describes the development and operation of the teaching module. Section 4 reports the analytical results of the teaching experiment. Section 5 provides the conclusions. Figure 2: Using the TEM to observe a material’s crystal structure.