In this paper, 3D printing is combined with supercritical CO₂ foaming technology as a novel strategy for the manufacture of thermoplastic polyurethane (TPU) lightweight hierarchical structure, which has the advantages of high specific strength of microcellular foam and free design of 3D printing structure at the same time. More critically, the microstructure of the hierarchical structure presents a shell and core structure similar to the turtle shell, with the thickness of the shell layer and the size of the core layer's cells adjustable with 3D printing parameters, leading to changes in the mechanical properties of the printed foam. In further energy absorption tests, the hierarchical cellular honeycomb with high specific strength exhibits enhanced the specific energy absorption (SEA) by 9.56% compared with the unfoamed honeycomb. In addition, the SEA of TPU hierarchical cellular honeycomb can be adjusted in the range of 0.214–0.377 J/cm³ by changing the printing parameters, with the maximum energy absorption efficiency up to 0.383. Combined with the advantages of 3D printing personalization make the hierarchical cellular foam promising for a broad range of applications in fields such as personal shielding, energy absorption, and transportation.

本文将3D打印与超临界CO _{2发泡技术}相结合，作为一种制造热塑性聚氨酯（TPU）轻质分级结构的新策略，具有微孔泡沫比强度高、3D打印结构可自由设计等优点。同一时间。更关键的是，分层结构的微观结构呈现出类似于龟壳的壳核结构，壳层的厚度和核层细胞的大小可通过3D打印参数调节，从而导致力学性能的变化打印的泡沫。在进一步的能量吸收测试中，与未发泡蜂窝相比，具有高比强度的分级蜂窝蜂窝的比能量吸收（SEA）提高了9.56%。^{此外，TPU分层蜂窝蜂窝的SEA可以通过改变打印参数在0.214~0.377 J/cm 3}范围内调节，最大能量吸收效率可达0.383。结合3D打印个性化的优势，使得分层多孔泡沫在个人防护、能量吸收和运输等领域具有广泛的应用前景。