Abstract: ​Origami, the ancient Japanese art of paper folding, is not only an inspiring technique to create sophisticated shapes, but also a surprisingly powerful method to induce nonlinear mechanical properties. Over the last decade, advances in crease design, mechanics modeling, and scalable fabrication have fostered the rapid emergence of architected origami structure and material systems. They typically consist of folded origami sheets or modules with intricate three-dimensional geometries, and feature many unique and desirable mechanical properties like auxetics, tunable nonlinear stiffness, multi-stability, and impact absorption. Rich designs in origami offer great freedom to prescribe the performance of such origami structures and materials. In addition, folding offers a unique opportunity of fabrication at vastly different sizes. This talk will highlight our recent studies on the different aspects of origami-based structures and materials–geometric design, mechanics analysis, and achieved properties–and discusses the challenges ahead.