3D-Printed Prosthetic Hand Springs for Haptic Throw Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional 3D printed prosthetics lack the fine motor control and haptic feedback necessary for sports-specific tasks, particularly in upper extremity prosthetics, which limits their functionality and dexterity, especially in activities requiring precise force and positional control like basketball.
Innovation Solution
A multi-material 3D printed prosthetic hand with coil springs that provide energy return and haptic feedback, where the conductivity changes with strain, allowing users to sense the force applied during tasks like throwing a basketball, reducing the need for electronic components and enhancing control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional 3D printed prosthetics are used, then manufacturing simplicity and cost-effectiveness are maintained, but fine motor control and haptic feedback functionality are lost
Solution Approach 1:
The patent merges the structural spring component with the sensing function by embedding conductive material within the 3D printed spring structure. This integration allows the spring to simultaneously provide mechanical energy return and generate electrical signals through the piezoresistive effect, eliminating the need for separate sensors while maintaining manufacturing simplicity.
Solution Approach 2:
The patent utilizes the piezoresistive effect to change the electrical resistance parameter of the spring material in response to mechanical strain. This parameter change enables the spring to transduce mechanical deformation into electrical signals that can be processed for haptic feedback, adding sensing capability without complex electronics.
2Ease of manufacture
If conventional 3D printed prosthetics are used, then cost-effectiveness is maintained, but haptic feedback capability is lost
Solution Approach 1:
The patent replaces complex mechanical sensing systems with an electrical resistance-based sensing mechanism embedded in the spring. The piezoresistive material allows the spring to generate electrical signals proportional to applied strain, substituting mechanical measurement with electrical measurement for more efficient information capture.
Solution Approach 2:
The spring structure serves dual functions: providing mechanical energy return and generating haptic feedback signals. The spring itself becomes the sensor through the embedded conductive material, allowing it to self-report its deformation state without requiring external sensing components.
3Measurement precision
If traditional sensors and electronic components are added to prosthetics, then sensing capability is improved, but device complexity and weight increase
Solution Approach 1:
The patent combines the spring's mechanical function with the sensor function into a single integrated component. The conductive material is embedded within the spring structure during 3D printing, creating a unified element that both stores mechanical energy and generates electrical signals, thereby reducing device complexity.
Solution Approach 2:
The spring is designed to perform multiple functions simultaneously: mechanical energy storage and return, strain sensing through piezoresistance, and potential actuation. This multi-functionality reduces the overall number of components needed in the prosthetic system.
4Measurement precision
If traditional sensors and electronic components are added to prosthetics, then sensing capability is improved, but weight increases
Solution Approach 1:
The patent merges the spring component with the sensing function by embedding conductive material within the spring structure. This integration allows the spring to simultaneously provide mechanical energy return and generate electrical signals, eliminating the need for separate sensors and reducing overall weight.
Solution Approach 2:
The patent extracts the sensing function from separate electronic components and integrates it directly into the spring structure. By embedding conductive material within the spring, the sensing capability is obtained without adding the weight of traditional sensors, circuit boards, and associated electronics.
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 haptic feedback proportional to the force applied, simulating the biomechanics of a natural hand, thus improving athletic performance and user experience.
Implementation Method 1
a coil spring that provides energy return... The extent of the deformation or strain of the spring may be determined or estimated by measuring the conductivity or resistivity
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
Implementation Method 3
A haptic feedback generator may generate haptic feedback to the user proportionate to the conductivity (and the deformation) of the coil spring
Data Source
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.