Variable Stiffness Device Using Shape-Memory Segments

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing variable stiffness devices for flexible members, such as endoscopes, lack the ability to efficiently and precisely control stiffness across different areas, limiting their versatility and application in medical and industrial contexts.

Innovation Solution

A variable stiffness device comprising a first elongated member with alternating high-bending and low-bending stiffness portions, a second elongated member with shape-memory members, and a heater to transition the shape-memory members between low-stiffness and high-stiffness states, allowing for controlled stiffness variation by heating and cooling specific areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a variable stiffness device uses shape-memory members spaced apart with connecting members between them, then the device can vary stiffness in specific areas, but the structure becomes more complex

Engineering Contradiction:

Improvestiffness variation capabilityVSAvoidstructural complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The flexible member is divided into multiple segments including shape-memory members spaced apart from each other, with connecting members between adjacent shape-memory members. This segmentation allows independent stiffness control of each shape-memory member while maintaining overall flexibility, resolving the contradiction between adaptability and complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The device employs movable shape-memory members that can transition between different stiffness states dynamically. The shape-memory members can be moved relative to each other along the flexible member's length, enabling real-time adjustment of stiffness characteristics without permanent structural changes.

Inventive Principle:

Principle #15Dynamics

2Measurement precision

If the device provides different degrees of stiffness to different areas of the flexible member, then precision control is improved, but the device complexity increases

Engineering Contradiction:

Improvestiffness control precisionVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Different portions of the flexible member are equipped with shape-memory members that can be independently actuated. Each shape-memory member can be heated or cooled separately to provide locally tailored stiffness characteristics, achieving precise spatial control without requiring a completely separate mechanism for each location.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The stiffness of each shape-memory member is controlled by changing its temperature parameter. By heating or cooling specific shape-memory members independently, the device achieves precise control over local stiffness characteristics through simple thermal parameter changes rather than complex mechanical adjustments.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If shape-memory members are arranged in low-bending stiffness portions to be heated for stiffness increase, then stiffness control is improved, but heat transfer efficiency may decrease

Engineering Contradiction:

Improvestiffness controlVSAvoidheat transfer efficiency

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

Heating elements are positioned as intermediaries between the external heat source and the shape-memory members. These heating elements facilitate efficient thermal energy transfer to the shape-memory members, reducing energy losses and improving the overall heat transfer efficiency while maintaining ease of stiffness control.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Enables precise control of stiffness across different areas of the flexible member, enhancing its flexibility and resistance to external forces, and improving responsiveness and ease of assembly, while reducing component complexity and wear.

Implementation Method 1

The shape-memory member may transition in phase from a first phase to a second phase by the heat supplied from the inducing members

Methodology Applied

Scientific EffectPhase transition: Phase Change

Implementation Method 2

at least one heater configured to heat at least one of the shape-memory members

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 3

a shape-memory member to which heat is transferred from the inducing members. The shape-memory member may transition in phase from a first phase to a second phase by the heat supplied from the inducing members

Methodology Applied

Scientific EffectShape memory effect: Shape Memory Alloy

Data Source

PatentUS11399704B2Variable stiffness device, endoscope, and method of varying stiffness of variable stiffness device

Publication Date: 2022.08.02 OLYMPUS CORPORATION(JP)

AI summary

A variable stiffness device includes a first elongated member including high-bending stiffness portions and a low-bending stiffness portion between adjacent high-bending stiffness portions, a second elongated member arranged along the first elongated member and including shape-memory members and a connecting member between adjacent shape-memory members, a heater to heat a shape-memory member in the low-bending stiffness portion to increase the bending stiffness, and a moving mechanism to move the second elongated member relative to the first elongated member. When the heater heats a first shape-memory member in the low-bending stiffness portion, a second shape-memory member next to the first shape-memory member is arranged in a high-bending stiffness portion.