Development of Periodic Cell Structures that Can Adjust Young's Modulus by Changing Line Width

In recent years, there has been active research and development of periodic cell structures with high specific rigidity and strength, and they have been applied to practical products such as shoe insoles and helmet liners. In this study, the aim was to apply periodic cell structures to cushioning products and achieve comfortable products by optimizing the density distribution of Young's modulus. First, we investigated the fabricable range of periodic cell structures using FDM (Fused Deposition Modeling) 3D printing and created a fabricable map. Next, we examined periodic cell structures capable of adjusting Young's modulus by changing the line width. As a result, by using Gyroid as the periodic cell structure and adjusting its line width with an appropriate period, it became possible to vary Young's modulus over a wide range. Furthermore, compression tests were conducted on specimens made of TPU, resulting in stress-strain curves showing a trend similar to that of cushions, and Young's modulus values comparable to those of cushions were obtained.