Article cites research by Nikhil Gupta, professor of mechanical and aerospace engineering at NYU Tandon School of Engineering.
… A team of New York University [Tandon School of Engineering] researchers has found a way to convert flat QR codes into complex features hidden within 3D-printed objects to foil any potential pirates. In a paper published to Advanced Engineering Materials, the team said the method can be applied to QR codes, barcodes and other passive tags. By placing them within the objects, the researchers said it does not compromise the part’s integrity, nor does it make itself obvious to anyone trying to reverse-engineer the part.