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.

A Novel One-Degree-of-Freedom Deployable Structure and Its Plate Form

Abstract

Deployable structures are widely utilized in various fields due to their ability to switch between a deployed working state and a folded storage state. This paper presents a new method for achieving plate forms in deployable structures, allowing the formation of closed surfaces suitable for covering purposes. Initially, a novel one-degree-of-freedom (one-DOF) deployable network is proposed, employing Bennett linkages and Bennett-based 6R linkages. Subsequently, the shape of the links in the network is modified to obtain a plate form consisting of equilateral triangular panels. The paper also conducts kinematic analysis, motion property examination, and bifurcation condition discussion to demonstrate the folding properties of the proposed mechanism. Additionally, a modified scheme is proposed to enable the structure to form a closed surface, and physical prototypes are used to validate all the results. Overall, the proposed method presents new possibilities for developing practical and versatile deployable structures with broader applications.

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