Adaptive Bra Straps With Shear Thickening Support for Exercise

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sports bras provide insufficient support during exercise, causing breast displacement and discomfort, while high-tensile strength bras are uncomfortable due to shoulder strap issues like digging and chafing.

Innovation Solution

Adaptive straps made of an elastic fabric with a polymer composite of silanol-terminated polydimethylsiloxane, boric acid, and a curing agent, providing low tensile strength at rest and high strength during oscillation, sandwiched between elastic fabric layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high-tensile strength elastic fabric is used in sports bras, then sufficient breast support during exercise is achieved, but shoulder strap comfort deteriorates due to digging and chafing

Engineering Contradiction:
Improvetensile strengthVSAvoidshoulder strap digging and chafing
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by using a shear thickening fluid treatment that changes the material's mechanical properties in response to applied force. The fabric remains soft and comfortable during static wear but becomes stiff and supportive during dynamic exercise movements, automatically adapting to provide support only when needed to prevent breast displacement.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameter of the fabric by applying a shear thickening fluid coating that alters the tensile strength and stiffness characteristics. The fluid concentration and distribution are controlled to achieve low static strength for comfort but high dynamic strength for support, resolving the contradiction between comfort and support.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If ordinary bra is worn during exercise, then wearing comfort is maintained, but breast support during exercise is insufficient causing breast displacement

Engineering Contradiction:
Improvewearing comfortVSAvoidbreast support
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent makes the bra strap dynamically adaptive by incorporating shear thickening fluid that remains inactive during comfortable daily wear but activates during exercise movements. This allows the same strap to provide both comfortable daily wear and sufficient exercise support without requiring different products.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The bra strap performs self-adjustment through the shear thickening fluid that automatically responds to movement conditions. The fluid thickens in response to shear forces generated during exercise, providing support without external intervention or user adjustment, while maintaining comfort during static wear.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If shear thickening fluid with high diluent ratio is used, then adaptive performance is achieved, but manufacturing safety deteriorates due to flammable and easily vaporized diluent

Engineering Contradiction:
Improveadaptive performanceVSAvoidmanufacturing safety
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical parameters of the shear thickening fluid formulation by reducing the diluent ratio and selecting non-flammable alternatives. The fluid maintains its shear thickening properties for adaptive performance while using safer, non-vaporized additives that eliminate flammability risks during manufacturing and wear.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive and hazardous diluents with safer, more stable alternatives that may be less expensive and eliminate safety concerns. The alternative fluids provide the same functional performance without the harmful properties, making the manufacturing process safer and potentially more economical.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 adaptive straps offer comfortable support during daily activities and sufficient breast stability during exercise, with a thickness of less than 2 mm and a load strength of at least 7N at 10% static stretching, maintaining stability during 3.0 Hz vibration.

Implementation Method 1

adhesive layer having a first strength modulus x during static loading and a second strength modulus of at least 2x during dynamic loading of at least approximately 3Hz oscillation

Methodology Applied
Scientific EffectShear thickening: Shear Thickening

Data Source

PatentEP4401596B1Adaptive straps for brassiere products and the method of making the same
Publication Date: 2026.04.15 FOUR K KNITTERS
  • EP4401596B1 patent drawingFigure 1A~1B
  • EP4401596B1 patent drawingFigure 2~3
  • EP4401596B1 patent drawingFigure 4~5

AI summary

Provided is an adaptive strap for brassieres having at least one adaptive material layer (10) having a first strength modulus x during static loading and a second strength modulus of at least 2x during dynamic loading of at least approximately 3Hz oscillation. The adaptive layer (10) is sandwiched between two or more elastic fabric layers (20). The adaptive strap is extendable up to 100%of its initial length during low wearer activity but is extendable not more than 50%during vigorous wearer activity, providing support during exercise and comfort during daily use. In one aspect the adaptive material is a reaction product formed by reacting a silanol terminated polydimethylsiloxane, polymer matrix, boric acid and optional fillers. The adaptive material (10) is cured in situ within the elastic fabric layers (20).