SWCNTs consist of a single layer of graphene rolled into a cylindrical tube which allows electrons to move more freely along the tube's surface resulting in minimal scattering of electrons, making them metallic or semiconducting but structurally weaker on their own because they are only one atom thick and so they are more susceptible to bending and structural deformations. Where as in MWCNTs multiple layers makes it sturdier and more resistant to structural damage, robust but also more prone to defects and interlayer sliding, which reduces electrical performance compared to SWCNTs.