Bionic Elbow Joint With Compliant Elastic Link
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current prosthetic joints for upper body limbs, particularly elbows, lack the necessary reliability, comfort, and natural motion to perform everyday tasks effectively, and often have issues with weight, shape, and interaction with the environment.
Innovation Solution
A compliant joint design featuring rigid links connected by an elastic link and string sections that allow for relative rotation, mimicking natural joint movements, providing compliance and flexibility, and enabling out-of-plane rotations, with string sections driving the rotation in the principal plane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid hinge joint is used in prosthetic elbows, then structural strength and stability are improved, but natural motion and compliance deteriorate
Solution Approach 1:
The patent applies dynamics by transitioning from a static rigid hinge to a dynamic compliant joint that adapts its behavior. The elastic link allows the joint to dynamically adjust its compliance based on operational conditions, enabling natural motion patterns while maintaining structural integrity through the combination of rigid and compliant elements.
Solution Approach 2:
The patent implements parameter changes by modifying the joint's mechanical properties through the elastic link, which changes the stiffness and compliance parameters of the joint. This allows the joint to exhibit variable compliance, adapting between more rigid and more compliant states to balance strength requirements with natural motion capabilities.
2Adaptability or versatility
If compliant joint design is used, then natural motion and comfort are improved, but load-bearing capacity deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the joint structure into distinct rigid and compliant segments. The rigid links provide load-bearing pathways while the elastic link provides compliance, allowing each segment to specialize in its optimal function. This segmentation enables the system to achieve both natural motion and adequate load-bearing capacity.
Solution Approach 2:
The patent employs composite materials by combining rigid materials for the links with elastic materials for the connecting link. This composite approach allows the structure to simultaneously exhibit high stiffness where needed for load-bearing and high compliance where needed for natural motion, resolving the contradiction between these two requirements.
3Shape
If passive cosmetic prostheses are used, then aesthetic value is improved, but functional capability deteriorates
Solution Approach 1:
The patent implements universality by designing a joint that serves multiple functions simultaneously. The compliant joint mechanism provides both cosmetic appearance (through natural motion patterns) and functional capability (through adaptive compliance and natural movement), eliminating the need to choose between aesthetics and function.
Solution Approach 2:
The patent applies self-service through the compliant joint's ability to automatically adapt its motion characteristics without external control systems. The joint naturally produces physiologically realistic movement patterns through its mechanical compliance, providing both aesthetic and functional benefits without requiring complex control mechanisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design enhances the reliability and comfort of prosthetic joints by allowing natural motion, absorbing shocks, and enabling safe interaction with the environment, while supporting expected loads during daily tasks.
Implementation Method 1
a compliant joint (16) rotatably connecting the first rigid link (12) and the second rigid link (14)... The compliant joint (16) comprises an elastic link (18) extending between the first rigid link (12) and the second rigid link (14), wherein rotating the first rigid link (12) and the second rigid link (14) with respect to each other deforms the elastic link (18)
Implementation Method 2
a first string section (20) and a second string section (22) both extending between the first rigid link (12) and the second rigid link (14)... shortening one of the first string section (20) and of the second string section (22) and lengthening the other one of the first string section (20) and of the second string section (22) drives a rotation of the first rigid link (12) and the second rigid link (14) with respect to each other
Data Source
Figure 1A~1C
Figure 2
Figure 3
AI summary
An artificial joint for a prosthesis or robot arm, the artificial joint comprising a first rigid link, a second rigid link, a compliant joint rotatably connecting the first rigid link and the second rigid link with respect to a principal plane of rotation, and comprising an elastic link extending between the first rigid link and the second rigid link, and a first string section and a second string section both extending between the first rigid link and the second rigid link, being arranged on opposite sides with respect to the compliant joint, such that shortening one of the first string section and of the second string section and lengthening the other one of the first string section and of the second string section drives a rotation of the first rigid link and the second rigid link with respect to each other in the principal plane of rotation.