Comment by fwlr

Theoretically, I guess it could - iron selenide superconducts when its electrons are all forced the outer ring, and physically stretching the material can cause force electrons to the outer ring. But the precision required to apply enough tension to pull the electrons of every single atom into that state is absurd, and if some aren’t in that state then it won’t superconduct. Not to mention you also have to guarantee somehow that the material won’t do all the other things it normally does when physically stretched, like deform or break.