Core Viewpoint - Mobile manufacturers are increasingly focusing on the materials used for phone backs, as different materials not only provide varying tactile experiences but also allow for bolder designs [1][3]. Material Analysis - **Plastic Back**: Offers high practicality with low production costs, durability, and does not interfere with signal reception, making it a common choice. However, it lacks aesthetic appeal, leading to its relegation to entry-level models [4][6]. - **Glass Back**: Since the introduction of the iPhone 4, glass has become a mainstream choice for flagship phones due to its excellent moldability, electromagnetic permeability, and superior tactile feel compared to plastic and metal. Innovations like microcrystalline glass have emerged, combining the benefits of glass and ceramics [7][9][11]. - **Ceramic and Leather**: Ceramic backs provide a premium feel but are costly and fragile, limiting their use. Leather backs, while initially seen as a novelty, have gained traction for their aesthetic and functional qualities, including durability and heat resistance [14][16]. - **Fiberglass**: Recently introduced by Huawei, fiberglass backs offer a lightweight, durable, and visually appealing alternative, effectively addressing the shortcomings of other materials and allowing for innovative designs [21][23]. Evolution of Materials - The evolution of mobile phone materials reflects advancements in technology and changes in design philosophy, transitioning from plastic and metal to glass, ceramics, and fiberglass. This shift indicates a pursuit of balance between functionality, aesthetics, and user experience [24][26].