A method of constructing a superconducting switch includes depositing a thin sacrificial layer on top of a substrate. The sacrificial layer is patterned to remove portions of the sacrificial layer except at a first portion of the substrate. A superconducting metal layer is patterned on top of the substrate and on top of the sacrificial layer. The superconducting metal layer is patterned to form a superconducting metal line over the sacrificial layer. The patterned sacrificial layer is etched from under the superconducting metal line to release the metal line from the substrate.