Elastic Cage for SMA Tilt Module

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Solution Overview

Problem

SMA-based tilt modules face challenges due to high power consumption and premature wear caused by the need for partial actuation of SMA wires to achieve tilt, requiring careful balance and complex systems.

Innovation Solution

A tilt module subassembly comprising a cage made of elastic material with a Young modulus between 13000 and 16000 MPa, which absorbs strain from SMA wires, providing decoupling and return force, eliminating the need for dedicated counterbalance components like return springs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If SMA wires are used for tilt control, then reliability and power consumption are improved, but the high resistance to elongation causes premature wear and requires careful balance

Engineering Contradiction:
Improvesystem reliabilityVSAvoidcomponent lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent changes the material parameter of the cage from rigid (traditional metal) to elastic material with specific Young's modulus (10-20 GPa), enabling the cage to deform and absorb strain during SMA wire actuation. This parameter change allows the system to accommodate the high resistance to elongation of SMA wires without causing premature wear, while maintaining reliability benefits.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs an elastic cage structure that can deform flexibly during operation. This flexible cage absorbs the strain generated when SMA wires resist elongation, preventing stress concentration and premature failure of the SMA wires or fixing members, thereby extending component lifespan while maintaining system reliability.

Inventive Principle:
Principle #30Flexible shells and thin films

2Strength

If rigid fixing members are used to secure SMA wires, then mechanical fixation is achieved, but the system requires careful balance and becomes complicated

Engineering Contradiction:
Improvemechanical fixation strengthVSAvoidsystem complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent merges the functions of the cage and the fixing members into a single integrated elastic cage structure. The elastic cage inherently provides both mechanical fixation for SMA wires and the necessary flexibility to accommodate actuation forces, eliminating the need for separate rigid fixing members and reducing system complexity while maintaining fixation strength.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The elastic cage serves multiple functions simultaneously: it provides mechanical fixation for SMA wires, absorbs strain during actuation, and enables the tilt motion. This multi-functionality eliminates the need for separate dedicated fixing members, simplifying the overall system design while maintaining adequate fixation strength.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If SMA wires are partially actuated to achieve tilt, then tilt control is achieved, but power consumption increases

Engineering Contradiction:
Improvetilt control capabilityVSAvoidpower consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The elastic cage acts as an intermediary between the SMA wires and the tilt module. It absorbs and stores elastic energy during SMA wire actuation, reducing the energy required for partial actuation. The cage's elasticity allows it to return to its original position, recovering energy and reducing overall power consumption while maintaining ease of tilt 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

The elastic cage structure reduces power consumption and wear by decoupling opposing SMA wires, allowing for precise and controlled tilting with improved system performance and simplified design.

Implementation Method 1

SMA wires working opposite to each other in order to achieve the tilt control

Methodology Applied
Scientific EffectShape memory alloy contraction: Shape Memory Alloy

Implementation Method 2

heating, with the help of which the shape memory alloy wires can be actuated

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

The elastic cage structure reduces power consumption and wear by decoupling opposing SMA wires

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3268807B1Tilt module subassembly and optical image stabilizer comprising it
Publication Date: 2018.08.22 ACTUATOR SOLUTIONS
  • EP3268807B1 patent drawingFigure 1~2
  • EP3268807B1 patent drawingFigure 3~4
  • EP3268807B1 patent drawingFigure 5a~5b

AI summary

Tilt module subassembly comprising a cage (11) consisting essentially of elastic material and a plurality of shape memory alloy wires (12, 12') and optical positioning system for microstructures using such tilt module subassembly, wherein said optical positioning system for microstructures is an an optical image stabilizer.