Origami and kirigami have emerged as potential tools for the design of
mechanical metamaterials whose properties such as curvature, Poisson ratio, and
existence of metastable states can be tuned using purely geometric criteria. A
major obstacle to exploiting this property is the scarcity of tools to identify
and program the flexibility of fold patterns. We exploit a recent connection
between spring networks and quantum topological states to design origami with
localized folding motions at boundaries and study them both experimentally and
theoretically. These folding motions exist due to an underlying topological
invariant rather than a local imbalance between constraints and degrees of
freedom. We give a simple example of a quasi-1D folding pattern that realizes
such topological states. We also demonstrate how to generalize these
topological design principles to two dimensions. A striking consequence is that
a domain wall between two topologically distinct, mechanically rigid structures
is deformable even when constraints locally match the degrees of freedom.Comment: 5 pages, 3 figures + ~5 pages S