Vacuum Soft Gripper with Strain Limiting Layer
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Solution Overview
Problem
Conventional soft grippers face limitations in payload scalability, safety, and adaptability due to high positive pressures, material limitations, and design constraints, making them unsuitable for handling heavy industrial components and complex geometries.
Innovation Solution
A gripping apparatus with a multilayer finger membrane and phalange members formed from elastomers, featuring a strain limiting layer to prevent excessive stretching, and vacuum pressure actuation for bending, allowing for robust grasping and manipulation of various objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If positive pneumatic pressure is used to actuate soft grippers, then grasping force is improved, but safety and reliability deteriorate due to high pressure risks
Solution Approach 1:
The patent inverts the conventional approach by using negative pressure (vacuum) instead of positive pressure to actuate the soft gripper. The vacuum channel applies suction to the flexible membrane, causing it to deform and close the gripper fingers. This inversion maintains grasping force while eliminating the safety risks associated with high positive pressure systems.
Solution Approach 2:
The patent changes the pressure parameter from positive to negative, transforming the actuation mechanism. By using vacuum pressure (negative pressure) instead of pneumatic pressure (positive pressure), the system achieves the same grasping function with improved safety and reliability, as vacuum systems inherently cannot exceed atmospheric pressure.
2Adaptability or versatility
If conventional soft gripper materials are used, then flexibility is improved, but payload capacity deteriorates
Solution Approach 1:
The patent employs composite material construction by combining a flexible membrane material with a rigid internal structure (vacuum channel). The flexible membrane provides the necessary softness and adaptability to various object geometries, while the rigid vacuum channel structure provides the mechanical strength and stiffness required to handle heavy payloads. This composite approach resolves the contradiction between flexibility and payload capacity.
3Ease of manufacture
If simple single-layer membrane is used, then ease of manufacture is improved, but control precision deteriorates
Solution Approach 1:
The patent segments the membrane structure into multiple layers (first flexible membrane layer, strain limiting layer, second flexible membrane layer). This segmentation allows each layer to perform specific functions: the flexible layers provide compliance and sealing, while the intermediate strain limiting layer provides structural reference and control. The segmented design enables precise aperture control while remaining manufacturable through standardized layer assembly processes.
Solution Approach 2:
The patent introduces a strain limiting layer with specific mechanical properties between the flexible membrane layers. This local addition of material with different properties (higher stiffness, defined strain characteristics) provides precise control over membrane deformation and aperture size. The strain limiting layer creates a controlled interface that regulates the transmission of vacuum pressure, enabling accurate aperture control without complicating the overall manufacturing process.
4Device complexity
If no strain limiting layer is used, then device complexity is reduced, but stability deteriorates due to excessive stretching
Solution Approach 1:
The patent adds a strain limiting layer as a localized structural element within the membrane assembly. This layer has specific mechanical properties (defined strain characteristics, higher stiffness) that provide stability and prevent excessive stretching of the flexible membrane. The strain limiting layer is positioned strategically to maintain membrane integrity during vacuum actuation while preserving the overall simplicity and flexibility of the gripper design.
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 apparatus achieves improved force and aperture control, enabling the handling of heavy payloads and complex geometries while maintaining stability and safety, with the ability to lift objects up to several kilograms and manipulate delicate items.
Implementation Method 1
each of the plurality of finger members is configured to bend based on vacuum pressure actuation generated by the vacuum system via the opening of the coupling end portion of the finger member
Data Source
AI summary
A gripping apparatus includes a palm member; a plurality of finger members configured to couple to the palm member, each of the plurality of finger members comprising a plurality of phalange members arranged in series along a longitudinal axis of the finger member, each phalange member being formed of an elastomer; a multilayer finger membrane configured to encapsulate the plurality of phalange members, the multilayer finger membrane being formed of multiple material layers, including a strain limiting layer configured to limit the multilayer finger membrane from stretching; and a coupling end portion configured to couple to the palm member and includes an opening configured for fluid communication with a vacuum system, wherein each of the plurality of finger members is configured to bend based on vacuum pressure actuation generated by the vacuum system via the opening of the coupling end portion of the finger member.