Introduction of 3D Printing Technology in the Classroom for Visually Impaired Students

Abstract

As the importance of visual aids increases, textbooks are including more figures and images to help with students' understanding. These visual aids enable students to learn concepts more effectively by hearing and seeing them simultaneously. However, for students who are visually impaired (that is, blind or have low vision), reading and understanding a textbook poses challenges. Teachers of students who are visually impaired have difficulty teaching with textbooks because they are compelled to explain and describe the complex figures and content verbally. Even after being explained, the image or concept might still remain nebulous for the student. Therefore, to help both students and their teachers, instructional materials should be prepared with easy, cheap, and customizable methods such as three-dimensional (3D) printing. Instead of seeing and hearing, students can use their sense of touch to recognize the 3D tactile aids, which might improve their learning and memory processes. Recently, 3D printing technology has emerged as an exciting technological tool for creating sophisticated and custom-made objects with relatively low-cost materials (Melchels, Feijen, & Grijpma, 2010; Peltola, Melchels, Grijpma, & Kellomaki, 2008; Pham & Gault, 1998). 3D printing is the process of fabricating 3D objects by building up materials layer by layer with a specific layer thickness in the range of 100 to 400 micrometers (^m). The most important advantage of 3D printing is its ability to build new objects in a customized way. Thus, 3D printing can be a powerful tool to make tactile patterns or objects related to textbooks. Stangl et al. tried to make 3D-printed picture books for visually impaired children (Stangl, Kim, & Yeh, 2014). They transcribed the images of the classic book Goodnight Moon, by Margaret Wise Brown, by printing features with different plastic layers. However, this study presented only plane-based shapes and not complete 3D objects. In this research, we investigate how 3D printing technology could be utilized for instructional materials that allow visually impaired students to have full access to high-quality instruction in history class. Researchers from the 3D Printing Group of the Korea Institute of Science and Technology (KIST) provided the Seoul National School for the Blind with tactile instructional materials and resizable braille made by 3D printers as shown in Figure 1. The teacher provided side-by-side hands-on instruction to guide students in understanding the characteristics of the shapes and their meanings. Students also used their hands to independently explore the 3D materials, allowing them to appropriately feel the historical pictures, maps, or relics. This procedure reinforced delivery of the lecture immensely since it clarified potential misunderstanding of text descriptions. The resulting implication was that the 3D instructional materials were beneficial and more suitable to help visually impaired students successfully comprehend content taught in the classroom. METHODS Three different types of 3D printing methods were utilized: (1) fused deposition modeling (FDM); (2) three-dimensional printing (3DP); and (3) digital light processing (DLP). The 3D printing process involves multiple stages, as shown in Figure 2. All 3D printing techniques are based on the use of computer-aided design (CAD) information that describes the geometry and size of the objects to be printed. The CAD data is converted to an STL (STereoLithography) file format which has extensive triangular coordination of 3D surface geometry (Chen, Ng, & Wang, 1999). Once the file is in a printable format, the 3D model is sliced into a series of digital crosssectional layers of specific thickness. Then the designed structure is built through a layerby-layer fabrication process with each layer thickness being 100 |m. When the printing is completed, the last step involves post-treatment operations to the object to improve its softness, durability, and safety. …