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ORIGINAL RESEARCH article

Front. Robot. AI

Sec. Robot Design

Volume 12 - 2025 | doi: 10.3389/frobt.2025.1597271

Toward an Active Exoskeleton with Full Energy Autonomy

Provisionally accepted
Yakir  KnafoYakir Knafo1Yinjie  ZhouYinjie Zhou2Avi  ManorAvi Manor3Alon  OsovizkyAlon Osovizky3Raziel  RiemerRaziel Riemer2*
  • 1Mechanical Engineering, Tel Aviv University, Tel Aviv, Israel
  • 2Department of Industrial and Management, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
  • 3Electronics & Control Laboratories Nuclear Research Negev (NRCN), Beer Sheva, Israel

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

Exoskeletons aim to enhance human performance and reduce physical fatigue. However, one major challenge for active exoskeletons is the need for a power source. This demand is typically met with batteries, which limit the device's operational time. This study presents a novel solution to this challenge: a design that enables the generation of electricity during motions where the muscles work as brakes and absorb energy, with the energy stored and subsequently returned to assist when the muscles function as motors. To achieve this goal, a knee exoskeleton design with a direct drive and a novel electronic board was designed and manufactured to capture the energy generated by the wearer's movements and convert it into electrical energy. The harvested energy is stored in a power bank, and later, during motion, this energy is used to power the exoskeleton motor. Further, the device has torque control and can change the assistive profile and magnitude as needed for different assistance scenarios.Sit-to-stand (STS) motion was chosen as a test case for the first exoskeleton prototype. It was found that, during lowering (from stand to sit), the exoskeleton provided up to 10 Nm and harvested 9.4 J. During rising (from sit to stand), it provided up to 7.6 Nm and was able to return 6.8 J of the harvested energy. Therefore, the cycle efficiency of the exoskeleton system (return divided by harvesting) is 72.3%. In summary, this study introduces the first active exoskeleton for STS that can generate its own electrical power. The results show that the full development of this technology could reduce exoskeletons' need for external energy sources.

Keywords: Active exoskeleton, passive exoskeleton, harvesting energy, Returning energy, regenerating mode, motoring mode

Received: 20 Mar 2025; Accepted: 26 May 2025.

Copyright: © 2025 Knafo, Zhou, Manor, Osovizky and Riemer. 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: Raziel Riemer, Department of Industrial and Management, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel

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.