Jammkle: Fibre jamming 3D printed multi-material tendons and their application in a robotic ankle
This work addresses the need for improved soft robotic mechanisms in applications like robotic ankles, though it is incremental as it builds on existing fibre jamming concepts with new fabrication techniques.
The researchers tackled the problem of creating stiffness-tuneable robotic tendons by developing a novel, modular, multi-material 3D printed fibre jamming tendon unit called Jammkle, and demonstrated its application in a robotic ankle, showing it outperforms comparative leg structures in compliance, damping, and slip prevention.
Fibre jamming is a relatively new and understudied soft robotic mechanism that has previously found success when used in stiffness-tuneable arms and fingers. However, to date researchers have not fully taken advantage of the freedom offered by contemporary fabrication techniques including multi-material 3D printing in the creation of fibre jamming structures. In this research, we present a novel, modular, multi-material, 3D printed, fibre jamming tendon unit for use in a stiffness-tuneable compliant robotic ankle, or Jammkle. We describe the design and fabrication of the Jammkle and highlight its advantages compared to examples from modern literature. We develop a multiphysics model of the tendon unit, showing good agreement with experimental data. Finally, we demonstrate a practical application by integrating multiple tendon units into a robotic ankle and perform extensive testing and characterisation. We show that the Jammkle outperforms comparative leg structures in terms of compliance, damping, and slip prevention.