A research team in Australia addressed the gap between existing designs of soft prosthetic hands and the practical requirements highlighted in prosthetics research by considering the trade-offs between practicality and performance. Their design satisfied the practical design requirements, and the soft prosthetic hand can perform all the real-world grasping tasks of the benchmark tests, showing potential in improving quality of life for individuals with upper-limb loss.
The design incorporates 3D-printed soft materials that incorporate membrane-enclosed flexure joints in the finger designs, synergy-based thumb motion, and a cable-driven actuation system in the proposed hand prosthesis. The team’s systematic design, tentatively named X-Limb, weighs 253g, has three grasps types (with capability of individual finger movement), power-grip force of 21.5N, finger flexion speed of 1.3 seconds, minimum grasping cycles of 45,000 (while maintaining its original functionality), and material cost of $200 (excluding quick disconnect wrist but without factoring in the cost reduction through mass production), according to the study.
The practical application of the prosthesis was demonstrated through performance of real-world grasping tasks based on a standard Activities Measure for Upper-Limb Amputees benchmark test.
For more information, see the open-access study “A practical 3D-printed soft robotic prosthetic hand with multi-articulating capabilities” in PLOS One.