At the Interactive Structures lab, we work at the intersection of HCI + COMPUTATIONAL GEOMETRY + ENGINEERING + DESIGN. We investigate and develop interactive computational design tools that enable digital fabrication of complex structures for novice users. Interactive structures embed functionality within their geometry such that they can react to simple input with complex behavior. Such structures enable materials that can, e.g., embed robotic movement, can perform computations, or communicate with users. Such materials consist of many cells that open up complex topological spaces and allow for both theoretical contributions as well as real-world impact.