Piezoelectric Actuator Feedback for Optical Fiber Positioning

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Solution Overview

Problem

Actuating cantilevered optical fibers with piezoelectric actuators can be challenging due to inconsistent responses to actuator drive signals and changes over time, leading to deviations in intended movement and position, especially under varying environmental conditions.

Innovation Solution

The system detects voltages generated by the piezoelectric actuator during mechanical deformation to estimate its position and movement, using this feedback to improve actuation and maintain precise movement of the cantilevered optical fiber by adjusting actuator drive signals, and includes configurations for electrically decoupling the actuator driver from the piezoelectric actuator to prevent signal modification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a piezoelectric actuator is used to actuate the cantilevered optical fiber, then the optical fiber can be moved or vibrated in one or two dimensions, but the actuator's response to drive signals becomes inconsistent and deviates from intended movement over time

Engineering Contradiction:
Improvemovement speed of optical fiberVSAvoidactuation precision
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies feedback by detecting voltages generated by the piezoelectric actuator during mechanical deformation to estimate its position and movement. This detected feedback information is then used to adjust subsequent actuator drive signals, creating a closed-loop control system that compensates for drift and inconsistency, thereby maintaining reliable actuation precision over time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the operational parameters of the piezoelectric actuator by adjusting the actuator drive signals based on detected voltage feedback. This dynamic parameter adjustment allows the system to compensate for environmental changes and actuator drift, maintaining consistent movement precision despite variations in operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If voltages generated by the piezoelectric actuator are detected to improve actuation accuracy, then movement precision is enhanced, but electrical signals from the actuator driver may modify the detected voltages

Engineering Contradiction:
Improveposition detection accuracyVSAvoidsignal integrity
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the electrical connection by using separate conductive paths: one for applying actuator drive signals and another for detecting voltages generated during deformation. This segmentation prevents the actuator driver from modifying the detected voltage signals, preserving signal integrity while maintaining measurement precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary detection mechanism that measures voltages generated by the piezoelectric actuator during mechanical deformation. This intermediary approach allows position estimation without direct electrical coupling between the driver and detection circuitry, preventing signal modification while maintaining accurate measurement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of information

If separate conductive paths are used for actuation and detection, then signal integrity is maintained, but device complexity increases

Engineering Contradiction:
Improvesignal modificationVSAvoidelectrical connection structure
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent implements multi-functionality by using the piezoelectric actuator's inherent voltage generation capability for both actuation and sensing purposes. The same piezoelectric material serves dual functions: responding to applied voltages for actuation and generating detectable voltages during deformation for position feedback, thereby reducing overall system complexity.

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

Solution Approach 2:

The patent merges the actuation and sensing functions into a single piezoelectric actuator component. By utilizing the reverse piezoelectric effect for actuation and the direct piezoelectric effect for sensing, the system combines multiple functions into one element, simplifying the electrical connection structure while maintaining signal integrity through proper path separation.

Inventive Principle:
Principle #5Merging (Combining)

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

This approach enhances the accuracy and reliability of actuating cantilevered optical fibers by using real-time feedback from detected electrical signals to adjust actuation, reducing movement deviations and improving scanning precision.

Implementation Method 1

Voltages or other electrical actuation signals may be applied to the piezoelectric actuator. The applied electrical signals may mechanically deform or change the shape of a piezoelectric material of the actuator.

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

detecting voltages generated by the piezoelectric actuator due to mechanical deformation

Methodology Applied
Scientific EffectConverse piezoelectric effect: Converse Piezoelectric Effect

Data Source

PatentEP3054494B1Actuating an optical fiber with a piezoelectric actuator and detecting voltages generated by the piezoelectric actuator
Publication Date: 2018.09.26 UNIV OF WASHINGTON
  • EP3054494B1 patent drawingFigure 1
  • EP3054494B1 patent drawingFigure 2
  • EP3054494B1 patent drawingFigure 3

AI summary

A method of one aspect may include actuating a cantilevered optical fiber by mechanically deforming a piezoelectric actuator. An electrical signal generated as a result of mechanical deformation of the piezoelectric actuator may also be detected.