Embedding codes in internal structure of 3d printed object which can be scanned with tetraherz imaging technology.
http://www.karlddwillis.com/projects/infrastructs/
http://www.karlddwillis.com/wp/wp-content/uploads/2011/03/SIGGRAPH2013-InfraStructs.pdf
Here are similar technologies:
http://diy3dprinting.blogspot.com/2013/02/flomio-embeds-nfc-into-your-3d-models.html
I also remember that there was a post about similar DIY project but I just can not find it ...
http://www.karlddwillis.com/projects/infrastructs/
http://www.karlddwillis.com/wp/wp-content/uploads/2011/03/SIGGRAPH2013-InfraStructs.pdf
Here are similar technologies:
http://diy3dprinting.blogspot.com/2013/02/flomio-embeds-nfc-into-your-3d-models.html
I also remember that there was a post about similar DIY project but I just can not find it ...