Polymer Optical Metamaterial Sensor for Strain and Temperature

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Solution Overview

Problem

Existing optical components, particularly those based on silicon, are brittle, energetically complex, and costly to produce, limiting their use and reliability in applications such as optical communications and strain gauges.

Innovation Solution

An optical component with a polymer substrate featuring a first and second refractive index, formed through point-to-point exposure with a short-pulse laser or doping, which creates a metamaterial with periodically arranged pixels for efficient optical signal manipulation and strain/temperature measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silicon-based optical components are used, then optical signal manipulation capability is achieved, but the component becomes brittle and costly to produce

Engineering Contradiction:
Improvemechanical robustnessVSAvoidproduction cost and complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter from silicon to polymer, fundamentally altering the mechanical properties (from brittle to flexible) and manufacturing characteristics. This material substitution resolves the contradiction by providing both mechanical robustness and ease of manufacture through lower-cost polymer processing techniques.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure by embedding metallic nanoparticles (gold, silver, or aluminum) within a polymer matrix. This composite approach combines the flexibility and ease of manufacturing of polymers with the optical manipulation capabilities previously requiring silicon, while the nanoparticles provide the necessary optical functionality without the brittleness of pure silicon.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If silicon substrate is used for optical metamaterial, then optical signal manipulation is enabled, but energy consumption increases and production becomes complex

Engineering Contradiction:
Improveoptical signal manipulation capabilityVSAvoidenergy consumption during production
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the production method parameters from high-energy silicon fabrication to lower-energy polymer processing. The polymer can be processed at lower temperatures and with simpler techniques, dramatically reducing energy consumption while maintaining optical functionality through the embedded metallic nanoparticles.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent adopts polymer materials that are inherently cheaper and easier to process than silicon. The polymer substrate can be manufactured using cost-effective methods such as spin coating, dip coating, or inkjet printing, eliminating the need for expensive silicon fabrication facilities and reducing overall production energy requirements.

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

3Ease of manufacture

If polymer substrate is used, then manufacturing cost decreases and robustness improves, but measurement precision may be affected

Engineering Contradiction:
Improvemanufacturing cost-effectivenessVSAvoidstrain and temperature measurement accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent uses composite materials (polymer with metallic nanoparticles) to maintain measurement precision. The metallic nanoparticles provide stable optical resonances that are sensitive to strain and temperature changes, ensuring high measurement accuracy despite the use of flexible polymer substrate. The composite structure compensates for any potential precision losses.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent creates local regions with high refractive index contrast by embedding metallic nanoparticles in specific patterns within the polymer. This local quality enhancement ensures that the measurement regions maintain high precision through strong optical field confinement and sensitivity, while the overall polymer substrate provides cost-effectiveness and robustness.

Inventive Principle:
Principle #3Local quality

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 polymer-based optical component is more cost-effective, robust, and capable of measuring strain and temperature with high sensitivity, offering improved reliability and versatility compared to silicon-based components.

Implementation Method 1

In other embodiments of the invention, thermal effects can be generated in the substrate material by means of laser radiation, which lead to a change in the refractive index.

Methodology Applied
Scientific EffectThermal effects: Heating

Implementation Method 2

The optical component comprises at least one region in which an optical metamaterial is formed... each of which comprises a region having the first or the second refractive index

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

The substrate exhibits a greater thermal expansion compared to silicon. This allows certain predefinable properties of the metamaterial to change, enabling the optical component to be used for temperature measurement.

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3299850B1Optical component, sensor and method for measuring an elongation and/or a temperature
Publication Date: 2024.07.31 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP3299850B1 patent drawingFigure 1~2
  • EP3299850B1 patent drawingFigure 3~4
  • EP3299850B1 patent drawingFigure 5~6

AI summary

The invention relates to an optical component (1) with a substrate (10) having a first refractive index, in which spatial regions (12) with a second refractive index are formed, wherein the optical component (1) contains at least one optical metamaterial (2) which contains a plurality of individual pixels (21, 22), each of which comprises a spatial region having the first or the second refractive index, and wherein the substrate (10) contains or consists of at least one polymer. The invention further relates to a sensor with such an optical component and a method for measuring strain and/or temperature.