Upper-Limb Prosthetic Springs With Piezoresistive Throw Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional 3D printed prosthetics lack the fine motor control and haptic feedback necessary for high-dexterity tasks, particularly in sports-specific applications, such as basketball, where precise force and positional feedback are crucial.
Innovation Solution
A prosthetic hand with coil springs that provide energy return and haptic feedback, made using multi-material 3D printing, where the conductivity changes with strain, allowing for sensing of force applied during tasks like throwing a basketball, reducing the need for electronic components and enhancing control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional 3D printed prosthetics are used, then manufacturing simplicity is maintained, but haptic feedback capability and fine motor control are lost
Solution Approach 1:
The patent combines the spring's mechanical function with the sensor function by integrating conductive material directly into the spring structure during 3D printing. The spring serves both as an energy storage element and as a strain sensor, eliminating the need for separate electronic sensing components while providing accurate haptic feedback capability
Solution Approach 2:
The patent uses composite materials by incorporating conductive material (such as conductive plastic or metal-infused filament) into the spring structure during multi-material 3D printing. This creates a spring that simultaneously possesses mechanical elasticity and electrical conductivity, enabling both energy return and strain sensing functions
2Measurement precision
If multi-material 3D printing with conductive material is used, then haptic feedback is enabled, but manufacturing complexity increases
Solution Approach 1:
The conductive material is pre-integrated into the spring structure during the 3D printing process itself, rather than being added as a separate component afterward. This preliminary integration of sensing capability into the manufacturing process reduces post-processing complexity and assembly steps
3Use of energy by moving object
If coil springs with energy return are used, then energy efficiency is improved, but device complexity increases
Solution Approach 1:
The spring provides energy return through its inherent elastic properties without requiring external power sources or complex control systems. The multi-material spring is self-powered, converting mechanical energy to electrical signals autonomously through its conductivity changes during deformation, eliminating the need for separate power and sensing systems
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 prosthetic hand enables users to perform tasks with less energy expenditure and greater fine-tuned control by providing energy return and haptic feedback, simulating the biomechanics of a natural hand, thus improving athletic performance.
Implementation Method 1
a coil spring that provides energy return and that has a conductivity that varies in relation to an amount of strain on the spring
Implementation Method 2
the springs are made by multi-material 3D printing (additive manufacturing). Such springs made by multi-material 3D printing may include a first material that is electrically non-conductive (insulative) and a second material that electrically conductive. The extent of the deformation or strain of the spring may be determined or estimated by measuring the conductivity or resistivity of the electrically conductive material portion of the spring
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
An upper-extremity prosthetic is adapted to engage with an athletic ball. The prosthetic includes one or more springs that provide energy return as a user is throwing the ball using the prosthetic. The springs can have a conductivity that changes in relation to an amount of strain or deformation of the spring. The change in conductivity can be used to provide haptic feedback to the user so the user can sense the amount of force being applied to throw the ball. In some embodiments, the springs are made by a multi-material 3D printing (additive manufacturing) process and include a first material that is electrically non-conductive and a second material that electrically conductive. In some embodiments, the prosthetic also includes one or more cantilevered springs that are also adapted to engage with the ball and to provide energy return while throwing the ball.