Shape Memory Hinge with Insulated Strand Bundle
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motorized articulation devices using shape memory materials face challenges such as sudden energy release, mechanical shocks, and high energy requirements, which are detrimental in applications like satellites where energy resources are limited and mass needs to be minimized.
Innovation Solution
A motorized articulation device utilizing a bundle of electrically conductive shape memory material strands, laterally insulated and connected in series, which can be heated by a low-intensity electric current to deform and provide controlled mechanical energy without sudden shocks, allowing for self-locking and controlled deployment/folding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high supply currents are used to heat the shape memory material sufficiently, then the mechanical energy output is improved, but the mass and bulk of power transformers increase
Solution Approach 1:
The patent divides the shape memory material into multiple strands that are electrically insulated from each other but mechanically connected. This segmentation allows the electrical current to be distributed across multiple parallel paths, reducing the current intensity required in each strand while maintaining the total mechanical energy output. The insulated strands can be heated more efficiently with lower intensity currents, eliminating the need for heavy power transformers.
Solution Approach 2:
The patent introduces electrical insulation between strands, adding a dimensional aspect (lateral insulation) to the strand arrangement. This insulation layer allows the strands to be electrically isolated while remaining mechanically connected, enabling parallel electrical heating paths without requiring high current intensity through a single conductor, thus reducing transformer requirements.
2Device complexity
If springs or Carpentier blades are used for motorization, then the device complexity is reduced, but mechanical shocks and vibrations occur during deployment
Solution Approach 1:
The patent changes the physical state and properties of the shape memory material through controlled heating. By gradually heating the insulated strands above their transformation temperature, the material undergoes a controlled phase transformation from martensitic to austenitic structure, producing gradual deformation rather than sudden energy release. This parameter change (temperature-controlled phase transformation) eliminates mechanical shocks while maintaining deployment functionality.
Solution Approach 2:
The patent replaces traditional mechanical spring-based motorization systems with a thermally-actuated shape memory material system. Instead of using elastic mechanical energy storage and release (which causes shocks), the invention uses controlled thermal energy to induce phase transformation and gradual deformation, substituting mechanical energy storage with thermal-energy-driven shape change.
3Force
If the shape memory material is heated sufficiently to provide enough mechanical energy, then the deployment force is improved, but the energy consumption increases
Solution Approach 1:
The patent segments the shape memory material into multiple electrically insulated strands that can be heated in parallel. This segmentation increases the overall electrical resistance of the system, allowing sufficient heating and mechanical energy generation with lower intensity currents. The distributed heating across multiple strands reduces total energy consumption while maintaining the required deployment force.
Solution Approach 2:
The patent creates a composite structure by combining multiple shape memory strands with electrical insulation material between them. This composite arrangement optimizes both the mechanical properties (through parallel strand configuration) and electrical properties (through increased resistance and distributed heating), achieving sufficient deployment force with reduced energy consumption compared to solid block heating.
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 device achieves controlled deployment/folding with reduced energy consumption and minimal mechanical shocks, maintaining structural integrity and efficiency in limited energy environments like satellites.
Implementation Method 1
each strand tending to deform in bending from a first shape towards a second stable shape when it is heated beyond a transformation temperature
Implementation Method 2
heating by Joule effect requiring high intensity
Data Source
Figure 1a~1c
Figure 2a~2c
Figure 3a~3b
AI summary
The device has a shape memory device comprising bundles (21, 22) of wire strands made of electrically conductive shape memory material e.g. one-way shape memory material. Each bundle comprises two power supply terminals between which the strands are electrically connected in series and are heated by Joule effect such that power supply of the bundle drives bending deformation effort of the bundle from an intensity value of electric current, passing through the strands, corresponding to heating of the strands beyond transformation temperature. An independent claim is also included for a space system comprising an articulation device.