Inspired by the growth characteristic of leaf epidermis cell walls: A bio-ITCLC core for supporting a flexible skin with combined morphing applications

Abstract

Inspired by low transverse and high vertical stiffness characteristics of leaf epidermis cell walls, a biomimetic Isosceles Trapezoid Corrugated Lattice Cellular (bio-ITCLC) core is designed and fabricated. The constitutive model of the bio-ITCLC sandwich panel under out-of-plane compression is built to demonstrate great potential of the bio-ITCLC core for decoupling the mutual restriction of small tangential and large normal stiffness of a flexible skin. After that, the variable stiffness, equating to the continually changing stiffness characteristic of epidermis cell walls, is introduced in the above constitutive model to capture the growth behavior of a leaf shape via epidermis cell divisions to study morphing mechanisms of a flexible skin. On this basis, by the supporting effect of self-adaption units in the bio-ITCLC core, with new circumstances, is proposed to be one promising approach for designing a flexible skin with the small tangential and large normal stiffness for multi-morphing applications.