The age of 3D printing, when every object so created can be
personalized, will increase the need for tags to keep track of everything.
Happily, the same 3D printing process used to produce an object can
simultaneously generate an internal, invisible tag, say scientists at Carnegie
Mellon University and Microsoft Research.
These internal tags, which the researchers have dubbed
InfraStructs, can be read with an imaging system using terahertz (THz)
radiation, which can safely penetrate many common materials. In
proof-of-concept experiments, Karl Willis, a recent Ph.D. graduate in
computational design at Carnegie Mellon, and Andy Wilson, a principal
researcher at Microsoft Research, have demonstrated several possible tag
designs and the THz imaging and data processing steps necessary to read them.