Abstract: The present invention provides a biaxially twisted structure having curved developable surfaces which can be represented by a simple net. The net is in a two-dimensional shape of two congruent rotationally symmetric convex polygons misalignedly connected along a shared edge. A three-dimensional shape of the structure can be reconstructed from the net by sequentially connecting its edges. The structure has a unique design and mechanical feature, which can be utilized as a box, container, part, toy, building and so on.

Abstract: A panel and a system for use in building a lightweight structure are provided. The panel, made of a film or a sheet capable of being curved or bent with fingers, includes a body in a geometric shape circumscribed by straight or curved edges, and at least one joint formation along the edge for panel connection. The joint formation has tabs separated by at least one gap. Each tab expands bilaterally and proximally from the body at its base, and each gap is positioned along the edge so as to accept the base of the tab. The joint formations along the edges of varied curvatures are alignedly, hingedly, and detachably interlocked with each other by twisting the panels with fingers to individually hook the tab at the gap. The panels are assembled into geometric structures having flat or curved faces.

Abstract: A panel and a system for use in building a lightweight structure are provided. The panel, made of a film or a sheet capable of being curved or bent with fingers, includes a body in a geometric shape circumscribed by straight or curved edges, and at least one joint formation along the edge for panel connection. The joint formation has tabs separated by at least one gap. Each tab expands bilaterally and proximally from the body at its base, and each gap is positioned along the edge so as to accept the base of the tab. The joint formations along the edges of varied curvatures are alignedly, hingedly, and detachably interlocked with each other by twisting the panels with fingers to individually hook the tab at the gap. The panels are assembled into geometric structures having flat or curved faces.