The origami technique realizes unique mechanical properties of sheet materials without additional parts. In this study, a self-folded corrugated structure (SCS) is developed based on the reinforcing properties of the origami technique. The corrugated structures are employed as the core material for a high-strength, open-channel sandwich structure. Research on self-folded core materials is scarce; thus, a design concept is proposed, and the mechanical properties of the SCS are evaluated. First, the structural parameters of the SCS fabricated by changing the printing parameters (e.g., linewidth and number of lines/creases), to derive the structural model are determined. The model facilitates the design of an SCS with the desired structure. Thereafter, the mechanical properties of the SCSs are evaluated by conducting three-point bending tests to determine the essential design parameters corresponding to high stiffness. Moreover, SCSs can be stacked without occupying space, thus leading to improved strength. These SCSs fabricated using self-folding paper by ink-jet printing are low cost and eco-friendly. Moreover, they are specialized for rapid design and fabrication, depending on the application. This paper proposes the use of SCS as a novel smart core because it exhibits a high transportation efficiency and stiffness without additional components. Corresponding author(s) Email: ae18081@shibaura-it.ac.jp , hshige@shibaura-it.ac.jp