Designing Kresling Origami for Personalised Wrist Orthosis

TL;DR

This work presents a novel, Kresling origami-inspired wrist orthosis that combines topological variation with heat-sealable TPU fabric and a tendon-driven actuation system to achieve omnidirectional bending and multiple movement modes. The design enables personalised fit by partitioning the device into sections tuned to hand-wrist-forearm geometry, with six tendons driving bending through semi-folded origami units; experimental validation demonstrates basic motions (extension, flexion, radial/ulnar deviations) and complex motions (dart-throwing, circumduction) with measured bending angles up to $32.63^\circ$ and characteristic fit improvements observed via balloon pressure. The fabrication and testing pipeline shows promise for patient-specific rehabilitation devices, though limitations in manufacturing, complete tendon-configuration testing, and human-subject validation remain. Overall, the study provides a concrete, scalable foundation for personalised origami-based wrist orthoses with potential clinical and rehabilitative impact.

Abstract

The wrist plays a pivotal role in facilitating motion dexterity and hand functions. Wrist orthoses, from passive braces to active exoskeletons, provide an effective solution for the assistance and rehabilitation of motor abilities. However, the type of motions facilitated by currently available orthoses is limited, with little emphasis on personalised design. To address these gaps, this paper proposes a novel wrist orthosis design inspired by the Kresling origami. The design can be adapted to accommodate various individual shape parameters, which benefits from the topological variations and intrinsic compliance of origami. Heat-sealable fabrics are used to replicate the non-rigid nature of the Kresling origami. The orthosis is capable of six distinct motion modes with a detachable tendon-based actuation system. Experimental characterisation of the workspace has been conducted by activating tendons individually. The maximum bending angle in each direction ranges from 18.81° to 32.63°. When tendons are pulled in combination, the maximum bending angles in the dorsal, palmar, radial, and ulnar directions are 31.66°, 30.38°, 27.14°, and 14.92°, respectively. The capability to generate complex motions such as the dart-throwing motion and circumduction has also been experimentally validated. The work presents a promising foundation for the development of personalised wrist orthoses for training and rehabilitation.

Figures (7)

• Figure 1: Wrist motions and orthoses. (a) Basic movements. (b) Complex movements. (c) Working principles of wrist braces and robotic exoskeletons.
• Figure 2: Kresling origami-inspired wrist orthosis. (a) Orthosis structure on a hand-wrist platform. (b) Tendon arrangement. (c) Actuation system.
• Figure 3: Kresling origami and its bending motions. (a) Crease patterns of traditional Kresling origami, conical Kresling origami, and their folded configurations. (b) Bending motions of a semi-folded Kresling origami. The bending angle $\beta$ is roughly indicated for State 3.
• Figure 4: Design and fabrication of origami wrist orthosis. (a) Topological design to fit hand-wrist-forearm characteristics. (b) Detailed manufacturing steps.
• Figure 5: Experimental setups. (a) Balloons for custom fit evaluation. (b) Actuated wrist orthosis in the motion tracking system for workspace and movement characterisation.