Adaptable by design: encoding complex deformation profiles in mckibben artificial muscles
Year: 2025
Type: article
Abstract: • The octopus achieves complex arm deformations through local muscle interactions. • Local interactions within the embodiment of McKibben Muscles define global motion. • The sleeve’s braiding angle is the key structural parameter for its motion. • A modular McKibben Muscle embeds multiple motions due to smart design. • Global shape change is achieved without complex software or control systems. The octopus achieves intricate arm deformations through local muscle interactions rather than centralized coordination. Inspired by this principle, this study aims to develop embodied intelligent McKibben Artificial Muscles (AMs), in which global deformation is encoded directly into their physical structure. The key design parameter explored is the braiding angle, which governs the type and magnitude of motion. By spatially varying this angle along the actuator, we demonstrate embedded capabilities for local extension and contraction within a single AM. Additionally, a mismatch in braiding angles between opposing wire sets generates a twisting motion. To implement these variations, traditional braiding techniques were adapted for localized angle control. Within a single McKibben AM, a maximum strain of + 0.06 and minimum strain of −0.19 was measured. A twist angle of 100° was achieved using a 50.4° angle difference at 50 kPa actuation pressure. A final modular prototype demonstrated the integration of multiple motion modes within a single actuator body. These results highlight the potential of mechanically intelligent AMs to simplify actuation systems in soft robotics. Applications include wearable technologies such as exoskeletons and prosthetics, as well as bioinspired systems like artificial hearts or continuum robotic arms, where compact and adaptive actuation is essential.
Source: Materials & Design
Institution: Delft University of Technology
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,650
Funder: Technische Universiteit Delft
OpenAlex ID: W4416529864