Microfluidic Detection Chip with Slope Drainage and Magnetic Transport

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Solution Overview

Problem

Current microfluidic detection chips face challenges such as interference from whole blood filtration, sample waste, and complex assembly processes, which affect detection sensitivity and precision, particularly in clinical point-of-care settings for high-sensitivity biomarkers like procalcitonin, N-terminal pro-brain natriuretic peptide, and troponin I.

Innovation Solution

A self-driving and short-time centrifugation combined microfluidic detection chip with a three-layer structure, featuring a sample loading area with a slope structure and cylindrical convex drainage points, a double-sided adhesive layer dividing the sample flow channel, and a waste liquid tank area, allowing for capillary-driven sample flow and efficient chromatographic reaction without whole blood filtration, along with a fixing device for stability and a centrifugal detection device for high-speed operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If whole blood filtration is performed using a filtering membrane, then erythrocytes are removed from the sample, but detection interference occurs and sample is wasted

Engineering Contradiction:
Improvedetection accuracyVSAvoidsample waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The invention removes the filtering membrane component entirely from the microfluidic chip design. Instead of filtering whole blood through a membrane, the system allows whole blood to flow directly through the microfluidic channels to the detection area, eliminating the source of detection interference and sample waste associated with membrane filtration

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces magnetic particles as an intermediary carrier that binds to target analytes in whole blood. These magnetic particles facilitate the separation and detection process without requiring membrane filtration, thereby eliminating detection interference while preserving sample integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If serpentine tube-like reaction area is used, then the chip structure is compact, but sample remains in the channel which adversely affects detection sensitivity

Engineering Contradiction:
Improvechip sizeVSAvoiddetection sensitivity
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The invention transforms the static serpentine channel design into a dynamic system where magnetic particles actively transport the sample through the microfluidic channels. This dynamic transport prevents sample stagnation in the channels while maintaining a compact chip structure, thereby preserving detection sensitivity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention replaces the passive mechanical flow through serpentine channels with an active magnetic field-driven transport system. Magnetic particles respond to external magnetic fields to move samples through the chip, eliminating the need for complex channel geometries and preventing sample retention that reduces sensitivity

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

3Device complexity

If directly opening channels on the substrate is performed, then the chip structure is simple, but processing cost is high

Engineering Contradiction:
Improvechip structureVSAvoidprocessing cost
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The invention employs thin film technology to create the microfluidic chip structure. Thin films are deposited and patterned to form channels and functional areas, providing a balance between structural simplicity and manufacturing cost-effectiveness while enabling precise control over fluid flow paths

Inventive Principle:
Principle #30Flexible shells and thin films

4Device complexity

If centrifugal force is used to control liquid flow, then the system is simple, but liquid flow rate is too fast which is not conducive to chromatography reaction progress

Engineering Contradiction:
Improvesystem complexityVSAvoidliquid flow rate
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The invention replaces centrifugal force-driven flow with magnetic field-driven transport of magnetic particles. This substitution allows for precise control of sample movement through the microfluidic channels at optimal speeds for chromatography reactions, while maintaining system simplicity through the use of external magnetic fields rather than mechanical centrifugation devices

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

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 design enhances sample utilization efficiency, reduces non-specific binding, improves detection sensitivity, simplifies chip preparation and assembly, and allows for precise, high-sensitivity immunodetection suitable for clinical point-of-care applications, with reduced equipment requirements and faster analysis times.

Implementation Method 1

a sample flow channel is divided by an adhesive area and an adhesive-free area on the double-sided adhesive layer

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

the lower layer of the chip is provided with a slope structure or a groove

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 3

a centrifugal detection device for stability and a centrifugal detection device for high-speed operation

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3674713B1Microfluidic detection chip and centrifugal detection device
Publication Date: 2022.03.16 SHANGHAI IGENETEC DIAGNOSTICS CO LTD
  • EP3674713B1 patent drawingFigure 1~2
  • EP3674713B1 patent drawingFigure 3~4
  • EP3674713B1 patent drawingFigure 5~6

AI summary

The disclosure provides a microfluidic detection chip, a preparation method thereof, a fixing device and a centrifugal detection device. The detection chip comprises overlapped three layers. The upper layer of the chip includes a sample loading area and vents; the lower layer of the chip includes a waste liquid tank area in which a slope structure or a groove is disposed; the intermediate layer of the chip is a double-sided adhesive layer on which sample flow channels are divided by an adhesive area and an adhesive-free area. The self-driving and short-time centrifugation combined microfluidic detection chip technology designed by the present disclosure can solve inherent problems of traditional paper substrates, further improve sample utilization, detection speed and detection sensitivity in immunoassay, and the preparation and assembly of the chip are simple, has low requirement for the detection device, and can be conveniently applied to the clinical detection.