Kinematics and design of a rigid foldable origami robot

Abstract

“Origami” is an art of paper-folding. Recently, origami has been applied to the design of foldable robot structure. There are various folding techniques including the one we studied — Miura-ori. We designed a Miura-ori of non-zero thickness that 1) was made from rigid materials (rigid origami), and 2) contained self-similar units (modular origami). Our design has a maximum thickness of 6 mm, but can be folded up to 180° (complete fold)—equivalent to a zero-thickness origami. In this paper, we presented a novel design of rigid, foldable, modular origami, as well as derived constraints of joint design that enable a complete fold. Moreover, neodymium magnets were placed in the cores of each rotational axis in certain patterns. This not only allows for the structure to have characteristics of self-folding or self-unfolding, but also gives us the ability to control this robot structure using a current-induced magnetic field. When the magnetic field is on, the robot can switch from an unfolding position to a folding position. Such feature presents a potential for this structure to be used as a dynamic “spring” with an adjustable stiffness. This adjustability could be achieved by varying the input current applied to generate the magnetic field. Another application of this mechanism includes reducing shocks, and vibrations that are perpendicular to the structure.