SPATIAL COMPREHENSION OF CRYSTAL LATTICES THROUGH VIRTUAL REALITY APPLICATIONS

The great development and lower cost of Information and communication technologies (ICT) that has taken place in recent decades has allowed virtual reality (VR) to become a tool used in more and more fields. One of the advantages of VR is to offer the user the possibility to visualize concepts that might otherwise not be properly understood, thus improving their spatial comprehension. Materials science and engineering (MSE) is a discipline present in a large number of engineering degrees. One of the concepts studied in MSE subjects are crystalline systems, in particular the crystal lattices that form in space the atoms that compose materials. The traditional way in which this concept is taught requires students to be able to mentally recreate complex distributions of atoms located in a specific way in space. As a consequence, the correct learning of crystal systems may present some difficulties among engineering students. This paper presents an educational tool based on VR that has been designed to assist students in learning crystal lattices. The application developed consists of a virtual reality learning environment (VRLE) that simulates installations in which the user can explore different crystal lattices at their own pace and learn about other concepts associated with them. The VRLE described here is an application that runs on a computer and is operated via keyboard and mouse or via keyboard and touchscreen. The VRLE recreates a building with different rooms where the user can freely walk around in a similar way as he/she would in a first-person 3D videogame. When the user enters the main room he/she finds a museum with different stands in which each of the different Bravais lattices is displayed. By approaching each stand, the user can observe each type of lattice in detail, making use of different options: rotate, revolve, create transparent zones, section, zoom, etc. In addition, for each crystal lattice the VRLE offers various didactic applications focused on facilitating the understanding of various technical aspects, such as unit cells, directions and crystallographic planes, interstitial sites, etc. After applying this educational resource in the classroom, students reported a better spatial understanding of the concepts that are most difficult to visualize: interstitial sites (tetrahedral and octahedral), linear density in a specific crystal direction, planar density in a specific crystallographic plane, etc. The most valued aspects of this VRLE as indicated by the students were the following: (i) interactivity, (ii) possibility to rotate and revolve objects, and (iii) specific applicability of crystal lattices. On the other hand, it should be noted that the application facilitated the explanation of spatial concepts that usually present difficulties during the teaching-learning process.