Technique of Embedding information Inside 3-D Printed Objects by Using Two Color 3-D Printing

Abstract

We evaluated our previously proposed technique of invisibly embedding information inside a 3-D printed object by using two color 3-D printing and of nondestructively reading the embedding information from the object. In this technique, information is first embedded in the digital data for 3-D printing. Then, the information is also embedded inside a 3-D printed object when the object is fabricated with the data and a 3-D printer. The information inside the object is expressed by constructing the inside with fine domains different in physical characteristics from the main body. The structure of the fine domains inside the object is detected by utilizing nondestructive inspection, and the information is decoded from the detected structure. In the experiment, the main body was fabricated from blue resin that had high transmittance of the near-infrared rays. The fine domains were fabricated from white resin that had low transmittance of the near-infrared rays. Near-infrared transmittance imaging was used to detect the structure of the fine domains inside the object. The results obtained from the experiment indicated that the structure of the fine domains inside the object could be detected by eyesight. We demonstrated the feasibility of the technique.