Knitted Soft Actuators With Integrated Sacs for Wearable Flexion

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Solution Overview

Problem

Existing soft actuators face challenges in wearable applications due to material density, hardness, and production complexity, limiting design options and increasing labor costs.

Innovation Solution

A soft actuator design using knitted fabric layers with integrated sacs and pressurizing elements, produced via three-dimensional whole-garment knitting, allowing for adjustable rigidity and flexibility, and incorporating sensors for feedback control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If elastomeric materials are used for soft actuators, then thermal resistance and chemical resistance are improved, but material hardness and weight increase, limiting movement range in wearable applications

Engineering Contradiction:
Improvethermal resistance and chemical resistanceVSAvoidmaterial weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the material parameter from traditional elastomeric materials to textile-based materials, fundamentally altering the weight and flexibility characteristics while maintaining the soft actuator functionality. This parameter change enables wearable applications by reducing weight and increasing flexibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material construction by combining textile layers with fluid-filled chambers, creating a hybrid structure that integrates the advantages of both material types. The textile provides flexibility and comfort while the fluid chamber provides actuation capability.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If textile-based soft actuators are developed, then material flexibility and weight are improved, but production complexity and labor costs increase due to sewing and attaching cut pieces

Engineering Contradiction:
Improvematerial weightVSAvoidproduction steps
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent merges multiple production operations into a single knitting process. The actuator components are integrated into a single knitted structure, eliminating the need for separate cutting, sewing, and attaching operations. This consolidation dramatically reduces production complexity and labor costs.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent achieves homogeneity in the actuator structure through continuous knitting, creating a uniform integrated structure without seams or joints. This homogeneous construction simplifies both manufacturing and the actuator's mechanical behavior.

Inventive Principle:
Principle #33Homogeneity

3Duration of action of stationary object

If elastomeric materials are used, then durability is improved, but design options are limited when scaling to different sizes

Engineering Contradiction:
ImproveenduranceVSAvoiddesign options
Core Design Contradiction:
Duration of action of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic adjustability to the actuator system through independent pressure control of different chambers. This allows the actuator to adapt its behavior and movement characteristics in real-time, providing versatile design options for different applications and scales while maintaining durability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the actuator into multiple independently controllable chambers or regions. This segmentation enables different parts of the actuator to perform different functions or move independently, greatly expanding design options and adaptability across various scales and applications.

Inventive Principle:
Principle #1Segmentation

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 design enables adaptable, lightweight actuators with enhanced movement range and reduced production costs, suitable for wearable devices and rehabilitation equipment.

Implementation Method 1

a soft actuator (1) which can be moved by means of fluid pressure between a first state in which it extends along a direction and a second position in which it is twisted away from this direction

Methodology Applied
Scientific EffectPneumatic pressure: Pressure Increase

Implementation Method 2

pressurizing elements that provide the regulation of the pressures of the first sac (5) and the second sac (6)

Methodology Applied
Scientific EffectPressure regulation: Pressure Increase

Data Source

PatentEP4330571B1Actuators for soft robotic applications
Publication Date: 2026.03.11 ISTANBUL TEKNIK UNIVSI
  • EP4330571B1 patent drawingFigure 1~2
  • EP4330571B1 patent drawingFigure 3~4
  • EP4330571B1 patent drawingFigure 5~8

AI summary

The invention is related to soft actuators controlled by fluid pressure. The actuators developed with the invention comprise two sacs which provide for the flexion of a structure upon pressurizing this structure that has an anisotropic flexibility, which is provided by different knitted layers. The knitted layers are produced as integrated with each other by means of the three-dimensional whole-garment knitting technique. The actuators according to the invention can be adapted according to the different requirements and produced with standard qualities.