Pleated Fluidic Artificial Muscle for Bidirectional Actuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pneumatic artificial muscles (PAMs) are limited by their inability to be embedded within complex structures, require cumbersome assembly steps, have high stress zones that reduce lifespan, and cannot easily switch between contraction and extension without complex designs.
Innovation Solution
A fluidic artificial muscle actuator made of a single, isotropic, flexible material with alternating ridges and valleys, allowing for both contraction and extension, manufactured through a single-step process without assembly, using a geometric model to optimize deformation and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If traditional PAMs use composite membranes with high tensile strength fibres and rigid terminal closures, then contraction force is improved, but device complexity and assembly difficulty increase
Solution Approach 1:
The patent merges the membrane and terminal closures into a single monolithic piece of flexible material. The closing portions are integral with the central portion, eliminating the need for separate rigid terminal closures and high tensile strength fibres. This integration reduces device complexity while maintaining the contraction force through the pleated structure's geometric design.
Solution Approach 2:
The patent uses a flexible membrane made of elastomeric material that forms both the chamber walls and the closing portions. This flexible shell approach replaces rigid terminal closures with deformable closing portions that can still provide structural support while allowing the overall structure to remain simple and manufacturable as a single piece.
2Force
If traditional PAMs require multiple components (fibres, terminal connectors, air chamber), then contraction performance is improved, but ease of manufacture and embedding capability deteriorate
Solution Approach 1:
The patent combines the air chamber and terminal connectors into a single monolithic flexible structure. The membrane with integrated closing portions eliminates the need for separate components that would require assembly, enabling the actuator to be manufactured in one piece and easily embedded within complex structures without cumbersome assembly steps.
Solution Approach 2:
The single flexible membrane structure performs multiple functions simultaneously: it forms the pressurizable chamber, provides the closing portions at both ends, and acts as the structural element that transmits force. This multi-functionality eliminates the need for separate specialized components, simplifying both manufacture and embedding applications.
3Strength
If traditional PAMs use rigid terminal closures and composite membranes, then structural strength is improved, but operational lifespan decreases due to high stress zones
Solution Approach 1:
The patent uses a flexible elastomeric membrane for both the chamber and closing portions, eliminating rigid terminal closures that create high stress concentration zones. The flexible material distributes stress more evenly throughout the structure, reducing wear and fatigue at connection points, thereby extending operational lifespan while maintaining sufficient structural strength through the pleated geometry.
Solution Approach 2:
The patent employs elastomeric materials with appropriate mechanical properties that provide both flexibility and sufficient strength. The material composition and pleated structure work together to distribute mechanical loads, avoiding the high stress concentrations that occur at rigid-flexible interfaces in traditional designs, thus improving durability.
4Force
If traditional PAMs are designed for contraction only, then contraction force is optimized, but adaptability to bidirectional actuation deteriorates
Solution Approach 1:
The patent designs the pleated membrane structure to be dynamically deformable in both compression and extension. The pleats can fold and unfold in response to pressure changes, allowing the actuator to naturally switch between contraction and extension modes. This dynamic geometric transformation enables bidirectional actuation without requiring complex additional mechanisms, maintaining contraction force while adding versatility.
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 actuator achieves high manufacturing simplicity, extended operational life, and efficient deformation in both directions, with scalable design parameters for customizable performance, suitable for complex structures and lightweight applications.
Implementation Method 1
a flexible membrane in the central portion interposed to said closing portions, said membrane having a plurality of ridges and valleys that alternate with each other in a circumferential direction around said axis to form a pleated structure
Implementation Method 2
The actuator achieves high manufacturing simplicity, extended operational life, and efficient deformation in both directions
Implementation Method 3
said single-step process is an additive manufacturing process
Implementation Method 4
said single-step process is a moulding process
Data Source
Figure 1
Figure 2a~2b
Figure 3
AI summary
Fluidic artificial muscle device comprising at least one pleated actuator (1 ) adapted to exert forces along an axis (K). Said actuator (1 ) comprises a chamber (10) delimited by closing portions (11) at the two opposite ends along said axis (K) and a flexible membrane (13) in the central portion (12) interposed to said closing portions (11). The membrane (13) has a plurality of ridges (130) and valleys (131) that alternate with each other in a circumferential direction around said axis (K) to form a pleated structure. Said actuator (1 ) consists of a single