Fluidic Actuator Manufacturing Method for Exoskeletons
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current exoskeleton systems lack efficient and compact fluidic actuators capable of generating high pressures, which limits their mobility and support capabilities, especially in wearable applications.
Innovation Solution
The development of fluidic actuators with a fluid-impermeable membrane and interfaces that can reach high pressures (5 psig to 100 psig or more), integrated into exoskeleton systems to provide enhanced mobility and support through inflatable structures and pneumatic systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If conventional fluidic actuators are used in exoskeleton systems, then the system structure is simpler, but the pressure generation capability is insufficient and mobility support is limited
Solution Approach 1:
The fluidic actuator is divided into multiple sealed chambers (first chamber and second chamber) with distinct functions. The first chamber generates pressure for plantar flexion while the second chamber maintains negative pressure for dorsiflexion, allowing independent pressure control and higher overall pressure generation capability without proportionally increasing complexity
Solution Approach 2:
The membrane is nested between the first and second chambers, serving as a common boundary that separates the two pressure zones. This nested structure allows the actuator to achieve complex multi-pressure functionality while minimizing the number of separate components and overall structural complexity
2Force
If high pressure fluidic actuators are developed, then mobility and support capabilities are enhanced, but the actuator size and volume increase
Solution Approach 1:
The actuator uses a flexible membrane as the primary structural element to separate and contain high-pressure chambers. This thin-film approach allows the generation of high forces and moments about the ankle joint without requiring large rigid housings or bulky pressure vessels, thus maintaining a compact actuator volume
Solution Approach 2:
The system employs pneumatic pressure differential across the membrane (positive pressure in first chamber, negative pressure in second chamber) to generate high forces. By utilizing fluid pressure directly to create the actuating force, the actuator achieves high moment generation about the ankle without mechanical leverage mechanisms that would increase volume
3Strength
If membrane material is welded to interface at high temperature, then bonding strength is improved, but the membrane material may melt or deform
Solution Approach 1:
The welding process parameters (temperature, time, pressure) are specifically optimized for the membrane material's thermal characteristics. By controlling the welding parameters within a narrow window, sufficient bonding strength is achieved without exceeding the membrane's melting or deformation temperature, thus resolving the contradiction between bond strength and material integrity
Solution Approach 2:
A support element acts as an intermediary between the welding tool and the membrane material during the welding process. This intermediary component protects the temperature-sensitive membrane from direct exposure to high welding temperatures while still allowing effective bonding between the membrane and the interface structure
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
These actuators enable improved mobility and support by generating significant moments about the ankle, allowing for efficient plantar flexion and dorsiflexion, enhancing user mobility and reducing exertion during walking and other activities.
Implementation Method 1
fluidic actuators with a fluid-impermeable membrane and interfaces that can reach high pressures (5 psig to 100 psig or more), integrated into exoskeleton systems to provide enhanced mobility and support through inflatable structures and pneumatic systems
Data Source
AI summary
A method of constructing an inflatable fluidic actuator that includes generating a tube configuration with one or more shapes of fluid-impermeable membrane material, the tube configuration having a first tube end and a second tube end and an internal tube face and an external tube face. The method also includes coupling a first and second interface to the tube configuration at the first and second tube ends by respectively coupling each interface to the tube configuration at a respective tube end by generating at least one of: a first circumferential bond between the fluid-impermeable membrane material and one or more sidewalls of the interface; and an external face bond between fluid-impermeable membrane material at the tube end onto an external face of the interface.