Asymmetric Soft Robotic Actuators for Pressure-Tuned Bending
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Solution Overview
Problem
Existing soft robotic manipulators have limited mobility and are not suited for applications requiring manipulation of delicate or varied objects, as they rely on rigid skeletons and lack adaptability in actuation dynamics.
Innovation Solution
The development of soft robotic actuators with a flexible or elastic elongate body that can be pressurized or depressurized, featuring a design with varying wall heights and pitches to enable specific pressure-actuated changes, allowing for bending and other complex motions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rigid robotic skeletons with conventional bearings are used, then structural strength and stability are improved, but adaptability for manipulating delicate objects and fitting into constrained spaces deteriorates
Solution Approach 1:
The patent replaces rigid robotic skeletons with soft robotic actuators composed of flexible elastomeric materials. These soft actuators can conform to delicate objects and fit into constrained spaces while maintaining sufficient structural integrity through pneumatic pressure and asymmetric geometric design. The flexible nature allows the robot to manipulate delicate objects without causing damage, resolving the contradiction between strength and adaptability.
Solution Approach 2:
The patent uses composite structures combining elastomeric materials with internal reinforcement elements such as braided mesh shells or rigidizing granular materials. This composite approach provides both the flexibility needed for adaptability and the structural strength required for support, allowing the actuator to maintain shape under pressure while remaining soft enough for delicate manipulation tasks.
2Force
If McKibben actuators with braided mesh shells are used, then contraction and extension capability is improved, but mobility and actuation dynamics are limited to a single mode
Solution Approach 1:
The patent divides the actuator body into multiple asymmetric unit cells with varying wall heights and pitches along the longitudinal axis. Each unit cell can undergo pressure-actuated bending independently, allowing the overall actuator to achieve complex multi-directional motions and variable curvature profiles. This segmentation enables rich actuation dynamics beyond simple contraction and extension.
Solution Approach 2:
The patent implements asymmetric wall thicknesses and varying geometric parameters (wall heights, pitches) at different locations along the actuator. This local variation in geometric quality creates pressure-sensitive bending with different curvature radii in different regions, enabling the actuator to perform complex motions such as curling, twisting, and multi-directional bending, thereby achieving versatile mobility and actuation dynamics.
3Adaptability or versatility
If soft robotic actuators with varying wall heights and pitches are used, then adaptability and complex motion capability are improved, but manufacturing complexity increases
Solution Approach 1:
The patent achieves complex motion capability by varying geometric parameters (wall heights, pitches, wall thicknesses) of the asymmetric unit cells. These parametric variations can be systematically designed and manufactured using additive manufacturing or other modern fabrication techniques, allowing complex geometries to be produced without proportionally increasing manufacturing complexity. The parametric design approach enables tuning of actuation dynamics while maintaining manufacturability.
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 achieve a broad and tunable dynamic range, reduced strain, and improved reproducibility, enabling them to perform complex motions and adapt to various applications, including medical devices and manipulation of delicate objects.
Implementation Method 1
a flexible or elastic elongate body that defines a sealed void which can be pressurized or depressurized relative to the environment surrounding the actuator
Implementation Method 2
The internal height of the elongate body varies over its length. Pressurizing or depressurizing the flexible or elastic elongate body causes at least a part of the flexible or elastic elongate body, and thus the actuator, to bend
Data Source
AI summary
A soft robotic actuator is disclosed. The actuator includes a first portion with a substantially constant profile and a second portion with a regularly varying profile, and bends in a pressure-dependent fashion as the internal pressure within the actuator is increased or decreased.