Fig. 5: Effects of mechanical and geometrical parameters on the mechanical behaviors of SFGMs.

a Strain–stress curves of SFGMs having different interface interactions (ϵ), where the dashed line is about the upper limit of stress. b Effect of ϵ on the key mechanical properties of SFGMs. c Strain–stress curves of SFGMs having different self-folded lengths (L0). d Effect of L0 on the key mechanical properties of SFGMs.