Shape-Formable Apparatus Using Fibrous Jamming for Tissue Stabilization

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Solution Overview

Problem

Existing shape-formable devices face limitations in achieving a balance between flexibility and rigidity, particularly in thin, sheet-like applications, as they either require significant volume for bulk media or lack extensibility and conformability due to high Young's Modulus materials, restricting their ability to assume complex shapes and apply sufficient forces for tissue stabilization.

Innovation Solution

A shape-formable apparatus comprising a gas-impermeable envelope with fibrous material that jams under reduced pressure, and optionally includes locking sheets with patterned solid and open regions, allowing for increased conformability and rigidity by moving solid regions relative to each other, enabling the apparatus to change from a flexible, formable state to a rigid, locked state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If bulk media is used to achieve shape-formability, then the device can be formed into desired shapes, but the volume required becomes significant and the device cannot be made thin or sheet-like

Engineering Contradiction:
Improveshape-formabilityVSAvoiddevice volume
Core Design Contradiction:
ShapeVSVolume of moving object

Solution Approach 1:

The patent uses a thin envelope containing fibrous material instead of bulk media. The envelope itself acts as a flexible container that can be formed into desired shapes while maintaining a thin profile, eliminating the need for large volumes of bulk jamming media.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent employs fibrous material with porous structure inside the envelope. This porous fibrous material can deform and conform to shapes while requiring minimal volume compared to discrete bulk particles, enabling thin-sheet applications.

Inventive Principle:
Principle #31Porous materials

2Strength

If high Young's Modulus materials are used to achieve rigidity, then the desired shape can be held, but the material cannot be easily extended within the plane and conformability is limited

Engineering Contradiction:
ImproverigidityVSAvoidconformability
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent segments the rigid structure into multiple thin layers of fibrous material separated by spacers. This segmentation allows each layer to conform independently while collectively providing rigidity when jammed, resolving the contradiction between holding shape and conforming to complex surfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces spacing between fibrous layers in the thickness dimension, allowing the material to extend and conform within the plane while maintaining rigidity through the stacked layer structure. This dimensional approach enables both conformability and shape-holding capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Length of moving object

If multiple thin layers are used to achieve low bending stiffness, then the article can be thin, but the layers cannot be extended within the plane and can only take on complex shapes by generating wrinkles

Engineering Contradiction:
Improvethin profileVSAvoidextensibility
Core Design Contradiction:
Length of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent uses porous fibrous material layers that can be extended within the plane. The porous structure allows fibers to slide and reposition relative to each other, enabling in-plane extension while maintaining the thin profile of multiple layered sheets.

Inventive Principle:
Principle #31Porous materials

4Stability of the object's composition

If the bending stiffness is increased under vacuum, then the multiple layers jam together and hold shape, but the conformability is lost as they behave like a single thick layer

Engineering Contradiction:
Improveshape stabilityVSAvoidconformability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent maintains segmentation of multiple thin layers even under vacuum conditions. The layers remain distinct and can still conform to complex shapes, while the jamming effect provides shape stability. This resolves the contradiction by preventing the layers from merging into a single thick layer.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses the thickness dimension with spacers to maintain layer separation and conformability even when jammed. The spaced architecture allows the stacked layers to conform to complex surfaces while providing rigidity and shape stability through the vacuum-induced jamming effect.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 a significant increase in stiffness and conformability, allowing it to maintain complex shapes and apply forces effectively for tissue stabilization while maintaining a thin, sheet-like configuration, overcoming the volume and extensibility limitations of existing devices.

Implementation Method 1

fibrous material positioned in the chamber that can jam or lock together to resist relative movement when the pressure in the chamber is reduced below ambient pressure

Methodology Applied
Scientific EffectJamming:

Implementation Method 2

reducing the pressure in the chamber to change the apparatus from the first state to a second state in which the apparatus has the desired shape and is substantially less formable than in the first state

Methodology Applied
Scientific EffectPressure reduction: Depressurisation

Data Source

PatentEP3234246B1Methods of using a shape-formable apparatus comprising fibrous material
Publication Date: 2020.01.29 3M INNOVATIVE PROPERTIES CO
  • EP3234246B1 patent drawingFigure 1A
  • EP3234246B1 patent drawingFigure 1B
  • EP3234246B1 patent drawingFigure 1C

AI summary

Method of using a shape-formable apparatus comprising fibrous material. A shape-formable apparatus can include an envelope defining a chamber, a port positioned to fluidly couple the chamber with ambience, and a fibrous material positioned in the chamber. The fibrous material can be substantially less formable when the apparatus is in the second state than when the apparatus is in the first state. The method can include providing the shape-formable apparatus in a first state; forming the apparatus into a desired shape; and reducing the pressure in the chamber to change the apparatus from the first state to a second state in which the apparatus is substantially less formable than in the first state.