Waveguide Particle Detection via Guided Light Scattering

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Solution Overview

Problem

Current particle detection methods, such as cryogenic electron microscopy, require complex and costly setups for immobilizing particles and have limited detection periods and sensitivity, especially for sub-100 nm particles, and often need specialized conditions and equipment.

Innovation Solution

A particle detection apparatus with a channel having sub-wavelength bore walls that uses coherent and incoherent light scattering to detect particles in a fluid, allowing for real-time tracking and enhanced sensitivity without the need for immobilization, using simpler monitoring devices and ambient conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If cryogenic electron microscopy is used to detect particles, then detection sensitivity is improved, but device complexity and cost increase significantly

Engineering Contradiction:
Improvedetection sensitivityVSAvoidsetup complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical immobilization systems with optical guidance. Instead of using mechanical stages and precise positioning mechanisms to hold particles stationary for imaging, the invention uses total internal reflection within a waveguide to confine and guide light along the channel, enabling detection of freely moving particles through their scattering effects on the guided light.

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

Solution Approach 2:

The patent changes the detection parameter from direct imaging (requiring particle immobilization) to light scattering measurement. By monitoring how particles scatter guided light within the waveguide, the system achieves high sensitivity without needing to freeze or mechanically constrain particles, thereby simplifying the overall setup.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If particles are immobilized for detection, then detection precision is improved, but detection period is limited

Engineering Contradiction:
Improvedetection precisionVSAvoiddetection period
Core Design Contradiction:
Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The patent enables continuous detection by allowing particles to move freely through the fluid-filled waveguide while continuously scattering light. The guided light mode persists along the entire channel length, providing ongoing illumination and scattering signals as particles flow through, eliminating the need for sequential immobilization and imaging steps.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If specialized conditions are used for particle detection, then detection sensitivity is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvedetection sensitivityVSAvoidoperational simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The waveguide structure itself provides the illumination function through total internal reflection, eliminating the need for external light sources and complex optical alignment. The guided light mode automatically confines and directs light along the channel, and particles passing through naturally scatter this light, with the scattering signals being collected by simple photodetectors positioned against the waveguide exterior.

Inventive Principle:
Principle #25Self-service

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 efficient detection of small particles with improved signal-to-background and signal-to-noise ratios, prolonged detection periods, and simultaneous measurement of scattering and fluorescence, reducing the complexity and cost of detection systems while maintaining high sensitivity.

Implementation Method 1

the channel being shaped to guide the light to propagate along the channel path

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

the channel being configured to let scattered light created in the channel path pass through the or each channel wall

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 3

a monitoring device configured to detect the scattered light that leaves the channel by passing through the or each channel wall

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Data Source

PatentEP3191814B1Particle detection apparatus
Publication Date: 2024.02.21 LEIDEN UNIVERSITY
  • EP3191814B1 patent drawingFigure 1~2
  • EP3191814B1 patent drawingFigure 3~5
  • EP3191814B1 patent drawingFigure 6

AI summary

There is provided a particle detection apparatus (30) comprising: a channel (32) including an inlet and at least one channel wall, the inlet permitting light to be introduced into the channel (32), the or each channel wall being arranged to define a channel path through which light may propagate; a light source (34) configured to introduce light into the channel (32) via the inlet, the channel (32) being shaped to guide the light to propagate along the channel path for illuminating a particle or a plurality of particles located in the channel path; and a monitoring device (36) configured to detect scattered light that is created by the illumination of the or each particle by the guided light and that leaves the channel (32) by passing through the or each channel wall.