The way I understood this is they developed the concentric ring pattern first, build a prototype using standard copper etching, and showed that it worked. Then

The way I understood this is they developed the concentric ring pattern first, build a prototype using standard copper etching, and showed that it worked. Then they showed they could achieve similar results by fabricating the same pattern using a laser and paper. Which means you need new readers. Readers that essentially are pretty fancy network analyzers. If they want to use current readers, they need a tag with logic gates, one that can send a digital response.