Latest Papers

ASME Journal of Mechanisms and Robotics

  • Investigation on a Class of 2D Profile Amplified Stroke Dielectric Elastomer Actuators
    on September 24, 2024 at 12:00 am

    AbstractDielectric elastomer actuators (DEAs) have been widely studied in soft robotics due to their muscle-like movements. Linear DEAs are typically tensioned using compression springs with positive stiffness or weights directly attached to the flexible film of the DEA. In this paper, a novel class of 2D profile linear DEAs (butterfly- and X-shaped linear DEAs) with compact structure is introduced, which, employing negative-stiffness mechanisms, can largely increase the stroke of the actuators. Then, a dynamic model of the proposed amplified-stroke linear DEAs (ASL-DEAs) is developed and used to predict the actuator stroke. The fabrication process of linear DEAs is presented. This, using compliant joints, 3D-printed links, and dielectric elastomer, allows for rapid and affordable production. The experimental validation of the butterfly- and X-shaped linear DEAs proved capable of increasing the stroke up to 32.7% and 24.0%, respectively, compared with the conventional design employing springs and constant weights. Finally, the dynamic model is validated against the experimental data of stroke amplitude and output force; errors smaller than 10.5% for a large stroke amplitude (60% of maximum stroke) and 10.5% on the output force are observed.

Design and Modeling of a Non-Flat Foldable Tubular Kirigami With Compliant Joints

Abstract

This paper applies the kirigami technique to a non-rigid foldable tubular origami to make a rigid foldable tubular design, i.e., a radially closable kirigami (RC-kiri). The laminar emergent torsional (LET) compliant joint is applied to surrogate the crease, which makes the design applicable in practical engineering applications. By incorporating a non-flat folding design, the folding angles of each crease are minimized, leading to a reduction in the strain exerted on engineering materials. The kinetostatic theoretical model is constructed using the principle of virtual work, and its results are compared with those obtained from a simulation model in finite element analysis (FEA). A 3D printed physical model is tested to obtain the relationship between forces and displacements. FEA and experimental results match with theoretical findings. This study builds a bridge between origami and kirigami and expands the application of LET joints to the fabrication of tubular kirigami.

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