Embedding and Detecting Patterns in a 3D Printed Object

This paper presents a technique for pattern embedding inside a real object fabricated with a 3D printer and a technique of detecting the pattern from inside the real object. The purpose of this technique is to hide information inside a real object by embedding patterns. The patterns are formed inside the object when the object is fabricated. The thermal conductivity of the pattern region differs from that of the other regions. Therefore, the pattern inside the object can be detected using thermography. In this study, we use plaster powder as the starting material, and the object is produced by sintering. However, the pattern region is formed by not sintering it, that is, the pattern region remains as powder. From the experiment, we find that we can detect patterns using thermography when the pattern size is 2 mm x 2 mm or larger, and we confirm the feasibility of this technique.