Shape Changing Composite Structure with Embedded SMA Actuators
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Solution Overview
Problem
Existing shape-changing composite structures face limitations such as requiring compressed air, high temperatures, or high voltages, and are often restricted to small deformations or predetermined folding patterns, making them inefficient for adaptive responses to environmental changes.
Innovation Solution
A multi-layer composite structure with a flexible surface element, integrated actuator, sensor, and control devices that can reversibly change its shape in response to environmental conditions, using active materials and a support device to achieve versatile deformation patterns without external energy carriers or complex drive systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If compressed air is used to inflate foil cushions for movement, then the surface can be moved and deformed, but external gases are required and space is needed both inside and outside the chambers
Solution Approach 1:
The shape memory alloy wires serve as self-contained actuators embedded within the composite structure. When electrically heated, they autonomously generate the forces needed for deformation without requiring external gas supply systems, thereby eliminating the need for external gases and complex inflation mechanisms.
Solution Approach 2:
The patent replaces the pneumatic mechanical system (compressed air inflation) with an electro-thermal actuation system using shape memory alloy wires. The electrical heating of SMA wires directly induces deformation through phase transformation, substituting the need for compressed air and pneumatic chambers.
2Adaptability or versatility
If shape memory alloy workpieces are heated for deformation, then the material exhibits shape memory properties, but the entire object must be heated and only small deformations of a few millimeters are achievable
Solution Approach 1:
Instead of heating the entire workpiece, the patent segments the actuation function into discrete shape memory alloy wire elements embedded at specific locations within the composite structure. Only the SMA wires are heated electrically, while the rest of the structure remains at ambient temperature, enabling localized and controlled deformation.
Solution Approach 2:
The patent applies shape memory alloy wires only in specific regions where deformation is needed, rather than heating the entire object. The embedded SMA wires provide localized actuation forces, creating large deformations only in the areas where the wires are positioned, thus avoiding global heating.
3Adaptability or versatility
If discrete mechanisms with active materials are used for surface texturing, then active modification is achieved, but the system complexity increases with multiple components
Solution Approach 1:
The patent merges the structural reinforcement function (fiber layers) with the actuation function (embedded shape memory alloy wires) into a single integrated composite structure. The SMA wires are embedded within the fiber-reinforced polymer matrix, combining structure and actuation into one unified system rather than separate discrete mechanisms.
Solution Approach 2:
The shape memory alloy wires serve multiple functions: they act as both the structural reinforcement elements and the actuation mechanisms. The same embedded wires provide both mechanical support to the composite structure and the active deformation capability, eliminating the need for separate actuator components.
4Extent of automation
If the composite structure changes shape in response to environmental conditions, then independent adaptation is achieved, but energy consumption increases
Solution Approach 1:
The shape memory alloy wires can be activated in periodic or pulsed manner rather than continuously. The control system can apply electrical heating only when shape change is needed, allowing the structure to return to its original shape passively or through reverse actuation, thereby reducing overall energy consumption compared to continuous actuation 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
Enables independent adaptation to environmental changes with large deformations and versatile folding patterns, requiring minimal energy and no external gases or fluids, enhancing aerodynamic, acoustic, and visual properties while maintaining compactness and efficiency.
Implementation Method 1
at least one shape memory alloy wire (5) embedded in the at least one fiber-reinforced plastic layer (4), wherein the at least one shape memory alloy wire (5) is configured to change its shape in response to a temperature change
Implementation Method 2
a heating element (3) integrated into the flexible surface element (2), wherein the heating element (3) is configured to heat the at least one shape memory alloy wire (5)
Data Source
Figure 1~2
Figure 3a~3b
Figure 4~6
AI summary
The present invention relates to a composite structure (1) that can change shape having a flexible planar element (2) which is designed to be reversibly transitioned from an initial state to at least one deformation state. In order to provide a composite structure (1) that can change shape and that can independently adapt to changing environmental conditions, the composite structure (1) according to the invention comprises a flexible planar element (2) which is designed to be reversibly transitioned from an initial state to at least two different deformation states, an actuator device (5) which is designed to transition the planar element (2) between the initial state and the at least two different deformation states, a sensor device (3) which is configured to capture data in relation to the composite structure (1) or the environment thereof and, based thereupon, to generate an output signal, and a control device (4) which is designed to control the actuator device (5) according to the output signal of the sensor device (3).