From the article: "The processors his team built were made using the flexible thin-film semiconductor indium gallium zinc oxide (IGZO), which can be built on pl

From the article: "The processors his team built were made using the flexible thin-film semiconductor indium gallium zinc oxide (IGZO), which can be built on plastic and continues to work even when bent around a radius of millimeters." It's not the plastic that conducts, instead it is the foundation which the conducting material is built upon.