Fresnel Diffraction Measuring Device for Thin Layer Swelling

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Solution Overview

Problem

Existing sensor configurations for measuring the swelling of thin layers, such as polyelectrolyte multilayers, are typically large, complex, and expensive, and often interfere with the sample, leading to inaccurate measurements as they can only provide independent information about thickness and layer quality, making it difficult to separately measure thickness and structural changes, which can result in false positives or negatives.

Innovation Solution

A measuring device and method utilizing Fresnel diffraction to evaluate the diffraction images of objects coated with sensor layers, where environmental properties like temperature, pressure, or pH influence the layer thickness, which in turn affects the diffraction pattern, allowing for the indirect measurement of these properties by analyzing the Fresnel diffraction patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional sensor configurations are used to measure layer swelling, then measurement capability is provided, but the device becomes large, complex, and expensive

Engineering Contradiction:
Improvelayer thickness measurementVSAvoidsensor configuration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical sensor configurations with an optical measurement system based on Fresnel diffraction. A simple optical setup consisting of a light source and detector measures the diffraction pattern of light passing through or reflecting from the layer, enabling thickness and structural measurements without mechanical contact or complex instrumentation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention creates an optical copy or representation of the layer structure through the Fresnel diffraction pattern. The diffraction pattern serves as an optical imprint that encodes information about the layer thickness and internal structure, allowing measurement without physically interacting with or disturbing the sample.

Inventive Principle:
Principle #26Copying

2Measurement precision

If conventional sensor methods are used, then some measurement data is obtained, but the sample is influenced and measurement accuracy decreases

Engineering Contradiction:
Improveswelling measurementVSAvoidsample interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The optical diffraction method creates a non-invasive optical copy of the layer structure. Light waves pass through or reflect from the layer without physically disturbing it, capturing the Fresnel diffraction pattern that represents the layer's thickness and structure. This eliminates mechanical contact and associated sample interference.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent introduces light waves as an intermediary between the measurement system and the sample. The optical field acts as a mediator that carries information about the layer structure without physically interacting with or altering the sample, enabling contactless and non-invasive measurement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If conventional sensor arrangements are used, then thickness measurement is possible, but separate measurement of structural changes cannot be achieved

Engineering Contradiction:
Improvethickness measurementVSAvoidstructural change information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The Fresnel diffraction pattern contains segmented or distributed information about different aspects of the layer structure. By analyzing different features of the diffraction pattern (such as fringe spacing, intensity distribution, and pattern morphology), the system can separately extract thickness information and structural information that would otherwise be conflated in conventional measurements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from one-dimensional thickness measurement to two-dimensional spatial frequency analysis of the diffraction pattern. The Fresnel diffraction pattern provides spatial frequency information that encodes both thickness and structural characteristics in different dimensional aspects, allowing simultaneous extraction of multiple parameters through Fourier analysis or other signal processing methods.

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

Enables accurate, non-invasive measurement of environmental properties by correlating changes in the sensor layer's diffraction pattern with the measured variables, such as temperature, pressure, or pH, without the need for large or complex sensor setups, providing independent measurements of layer thickness and structural changes.

Implementation Method 1

measuring device (100) for measuring a measurand (300) by means of a diffraction measurement, characterized in that an object (20) is located between the radiation source (10) and the radiation detector (25) in the beam path of the radiation source (10), the object (20) generating a diffraction pattern (22) which is measured by the radiation detector (25), wherein the diffraction pattern (22) is a Fresnel diffraction pattern

Methodology Applied
Scientific EffectFresnel diffraction: Fresnel Diffraction

Data Source

PatentEP2894461B1Measuring device and measuring method for measuring an indicator by means of a diffraction measurement
Publication Date: 2018.05.30 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP2894461B1 patent drawingFigure 1~2
  • EP2894461B1 patent drawingFigure 3~4
  • EP2894461B1 patent drawingFigure 5

AI summary

The invention relates to a measuring device for measuring a quantity by means of a diffraction measurement, comprising a radiation source (1) that emits radiation, an object (7-9) that is arranged in the beam path of the radiation source (1), and a radiation detector (5) that is arranged in the beam path of the radiation source (1) behind the object (7-9) and measures a diffraction pattern of the object (7-9), in particular a Fresnel diffraction pattern.It is proposed that the measured quantity is a property of an environment of the object (7-9), wherein the measured quantity influences an environment-dependent property of the object (7-9), such that the environment-dependent property of the object (7-9) reflects the measured quantity, while the environment-dependent property of the object (7-9) influences the diffraction pattern, so that the measured diffraction pattern of the object (7-9) reflects the environment-dependent property and thus also the measured quantity.