Compliant actuators that mimic biological muscle performance with applications in a highly biomimetic robotic arm

Yang, Haosen; Wei, Guowu; Ren, Lei; Yan, Lingyun; Caldwell, Darwin

Abstract

This paper endeavours to bridge the existing gap in muscular actuator design for ligament-skeletal-inspired robots, thereby fostering the evolution of these robotic systems. We introduce two novel compliant actuators, namely the Internal Torsion Spring Compliant Actuator (ICA) and the External Spring Compliant Actuator (ECA), and present a comparative analysis against the previously conceived Magnet Integrated Soft Actuator (MISA) through computational and experimental results. These actuators, employing a motor-tendon system, emulate biological muscle-like forms, enhancing artificial muscle technology. Then, applications of the proposed ac-tuators in a robotic arm inspired by the human musculoskeletal system are presented. Experiments demonstrate satisfactory power in tasks like lifting dumbbells (peak power: 36 W), playing table tennis (end-effector speed: 3.2 m/s), and door opening, without compromising biomimetic aesthetics. Compared to other linear stiffness serial elastic actuators (SEAs), ECA and ICA exhibit high power-to-volume (361 × 10 3 W/m 3) and power-to-mass (111.6 W/kg) ratios respectively, endorsing the biomimetic design's promise in robotic development.

• Journal Article Type: Article
• Acceptance Date: Jan 1, 2025
• Publication Date: 2025-01
• Deposit Date: Jun 29, 2025
• Publicly Available Date: Jun 30, 2025
• Journal: Advanced Bionics
• Peer Reviewed: Peer Reviewed
• Volume: 1
• Issue: 1
• Pages: 2-18
• DOI: https://doi.org/10.1016/j.abs.2024.12.001