Fig. 4: Combinatorial designs of 2D kirigami precursors for complex 3D shapes under uniaxial tension.
From: Boundary curvature guided programmable shape-morphing kirigami sheets
a–j Reconfigurable 3D shapes through bistability of discrete ribbons. a 2D precursor composed of 2 × 2 square units with zero boundary curvature. b–d Uni-axial stretching induced reconfigurable human face-like morphologies with switchable smiley (b) and sad (c) expressions, as well as eyeglasses (d) by tuning the popping directions of ribbons (insets). e 2D precursor composed of 3 × 1 rectangle units with zero boundary curvature. f, g Formation of switchable sinusoidal wavy and coiled shapes. h 2D precursor composed of an array of two circular units bridged with a biconcave unit. i, j Formation of a 3D encapsulated Venus flytrap-like shape through uniaxial stretching. k–n Formation of a 3D droplet-like shape (l) and vase-like shape (n) by uni-axially stretching 2D precursors with different combined boundary curvatures (k, m). Insets show the image of a droplet and a vase. o Formation of a flower-like shape by uni-axially stretching multiple layers of semi-circular 2D precursors. Scale bars = 10 mm.
