The present invention provides a self-healing field-effect transistor (FET) device comprising a self-healing substrate and a self-healing dielectric layer, said substrate and said layer comprising a disulfide-containing poly(urea-urethane) (PUU) polymer, wherein the dielectric layer has a thickness of less than about 10 μm, a gate electrode, at least one source electrode, and at least one drain electrode, said electrodes comprising electrically conductive elongated nanostructures; and at least one channel comprising semi-conducting elongated nanostructures. Further provided is a method for fabricating the FET device.