From the paper,

> This is, to the best of our knowledge, the first report of fully 3D-printed resettable fuses.

I think unique the contribution is that the entire circuit -- active and passive -- can be made with this one single material. Normally, you need to use many different materials and chemical baths to make a circuit with active components, but using this metal-polymer mix, you can _just_ deposit the metal and you are finished.