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ORIGINAL RESEARCH article

Front. Robot. AI
Sec. Human-Robot Interaction
Volume 12 - 2025 | doi: 10.3389/frobt.2025.1528266
This article is part of the Research Topic Wearables for Human-Robot Interaction & Collaboration View all 3 articles

OpenSEA: A 3D printed Planetary Gear Series Elastic Actuator for a Compliant Elbow Joint Exoskeleton

Provisionally accepted
Benjamin Jenks Benjamin Jenks 1Hailey Levan Hailey Levan 1,2Filip Stefanovic Filip Stefanovic 1*
  • 1 University at Buffalo, Buffalo, United States
  • 2 Messiah College, Mechanicsburg, Pennsylvania, United States

The final, formatted version of the article will be published soon.

    Next generation assistive robotics rely on series elastic actuators (SEA) that enable compliant human-robot interaction. However, currently there is a deficiency of openly available SEA systems to support this development. To address this, we propose a novel design of a compliant 3D-printed SEA device for elbow movement rehabilitation exoskeletons that we make openly available. The SEA design incorporates a planetary gear system and torsional spring, offering compliance, adaptability, and cost-effectiveness. Torque assessments of individual functional performance enabled us to use a 4.12 Nm motor at 26 RPM to achieve a max torque of 12.36 Nm at 8.67 RPM. A PID ensures precise movement of the motor at 0.26º per count to align with the desired user arm position. Moreover, the design of this SEA allows for easily adjustable parameters to fit different joints, or various torque output configurations. Qualitative testing confirmed spring compliance of 18.95º and elastic element compliance of 32.43º. This study presents a new 3D printed SEA design for compliant exoskeleton joints to enhance elbow rehabilitation or other assistive robots.

    Keywords: Series elastic actuator, 3D printed Exoskeleton, Rehabilitation, Compliant joint, assistive robotics

    Received: 14 Nov 2024; Accepted: 07 Feb 2025.

    Copyright: © 2025 Jenks, Levan and Stefanovic. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Filip Stefanovic, University at Buffalo, Buffalo, United States

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.