A practical main frame for convex-deformable mobile devices

• Published in: Smart materials and structures 2024-05, Vol.33 (5), p.55048
• Main Authors: Kim, Jeongil, Yu, Changmin, Jeong, Jaehyun, Jeong, Yoon Chang, Kang, Kiju
• Format: Article
• Language: English
• Subjects: auxetic structure; convex deformation; mobile device; PCB; sandwich plate
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/1361-665X/ad3ecf

In the existing mobile devices, such as iPads, the touchscreen & display assembly and the rear cover account for at least 60% of the total device weight. Therefore, device weight can be reduced significantly only by replacing these glass and metallic components with non-glass and polymeric equivalents. Recently, the authors’ research group demonstrated a monolithically polymeric sandwich plate that is convex-deformable, even with solid chips embedded in its cores. In this study, a new design of this sandwich plate is proposed to facilitate its use as a practical main frame of a mobile device. This design is validated by conducting finite element analyses and experiments involving three-dimensionally printed prototype of the proposed sandwich plate design. The plate is fabricated as two separate halves that are then assembled using snap-fits to form a single body. A flexible printed-circuit board with regularly arranged elliptical holes and many solid chips embedded on its upper and lower surfaces is accommodated within the core of the proposed plate. In addition, rib-like side covers and an overall latex coating are used to protect all four sides and the entire outer surface, respectively, without adversely affecting the overall convex deformation of the proposed plate design.