The mechanics characteristic of epidermis cell walls in a leaf growth process provides inspiration on a flexible multi-morphing skin

Abstract

The growth behavior of a leaf shape via epidermis cell division is important to design a flexible multi-morphing skin with small/large tangential/normal stiffness. The epidermis cell walls have four unique characteristics: cell unit's concave distribution, low transverse stiffness, high vertical stiffness, and the stiffness continually changes with new circumstances. Inspired by the epidermis cell unit's concave distribution/low transverse stiffness/high vertical stiffness, by theories and experiments is to build a constitutive model for the in-plane compressive sandwich panel with a biomimetic Isosceles Trapezoid Corrugated Lattice Cellular (bio-ITCLC) core. Then the constitutive model introduces a variable stiffness factor that is equivalent to the above changing stiffness characteristic caused by continuous epidermis cell division. On this basis, the bio-ITCLC core made up of movable self-adaptation units is proposed to be one promising supporting structure for helping a flexible multi-morphing skin get the larger normal stiffness without increasing its tangential stiffness.