Microfluidic Light Collection with Rotated Waveguides for Low-Noise Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Integrated optics in flow cytometers face challenges in creating perfectly directed illumination beams with low divergence and low divergence, leading to inefficiencies in existing technologies, resulting in background noise and noise, which affects the signal-to-noise ratio of the system, which limits the sensitivity of the signal-to-noise ratio in sample detection.

Innovation Solution

A light illumination and collection device for micro-fluidic systems, comprising a light source that emits light in a beam propagating in the cross-sectional plane of the flow channel, with a light collecting waveguide rotated relative to the projection of the cross-sectional plane, to collect sample information carrying light while avoiding background noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If integrated optics with diffraction gratings are used for illumination, then the device can be compact and integrated, but the illumination beam suffers from high divergence and creates background noise that reduces signal-to-noise ratio

Engineering Contradiction:
Improvedevice compactnessVSAvoidsignal-to-noise ratio
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The device segments the light collection function by using multiple waveguides oriented at different angles. Each waveguide collects light from specific angular ranges, separating the collection of sample information carrying light from the collection of background noise, thereby improving signal-to-noise ratio while maintaining compact integration

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces angular orientation as an additional dimension for light collection. By arranging waveguides at different angles relative to the illumination beam direction, the system selectively collects light based on its propagation angle, enabling separation of signal from background noise in the angular domain

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Use of energy by moving object

If illumination light is directed perpendicular to the flow channel, then the illumination is efficient, but side-scattered light and background noise are collected together reducing detection sensitivity

Engineering Contradiction:
Improveillumination efficiencyVSAvoiddetection sensitivity
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

Different waveguides are assigned different angular collection characteristics tailored to specific detection needs. Some waveguides are optimized for collecting side-scattered light at specific angles, while others collect forward-scattered light, allowing each waveguide to have specialized local quality for its intended detection function

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The waveguides are arranged asymmetrically with respect to the illumination beam direction, collecting light at different angles (both sides and forward direction). This asymmetric arrangement enables selective collection of sample information carrying light while avoiding the symmetric collection of background noise that would occur with isotropic collection

Inventive Principle:
Principle #4Asymmetry

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 device achieves a high signal-to-noise ratio by collecting sample information carrying light, such as side-scattered and forward-scattered light, while minimizing background noise, enabling efficient sample detection and analysis.

Implementation Method 1

causing light interaction between the illumination light and the sample to form sample information carrying light

Methodology Applied
Scientific EffectLight interaction: Scattering

Implementation Method 2

a light collecting waveguide configured to extend in a second plane parallel to the first plane, wherein the light collecting waveguide comprises a light inlet, wherein the light inlet and the light collecting waveguide are rotated in relation to a projection of a normal of the cross-sectional plane of the flow channel onto the second plane

Methodology Applied
Scientific EffectLight collection: Waveguide (optics)

Data Source

PatentEP4644863A1A light illumination and collection device and a method for light illumination and collection
Publication Date: 2025.11.05 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)
  • EP4644863A1 patent drawingFigure 1
  • EP4644863A1 patent drawingFigure 2
  • EP4644863A1 patent drawingFigure 3~4

AI summary

A light illumination and collection device (100; 200) for a micro-fluidic system comprises: a flow channel (110; 210) configured to extend in a first plane and allow flow of a sample through the flow channel (110; 210), a light source (120; 220) configured to transmit illumination light along an optical axis extending through a cross-sectional plane of the flow channel (110; 210) for causing light interaction between the illumination light and the sample to form sample information carrying light; a light collecting waveguide (130; 230) configured to extend in a second plane parallel to the first plane, wherein the light collecting waveguide comprises a light inlet (132; 232) configured to receive the sample information carrying light, wherein the light inlet (132; 232) and the light collecting waveguide (130; 232) are rotated in relation to a projection of a normal of the cross-sectional plane onto the second plane.