Flow Cell Pillar Design for Capillary Pump Capacity

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Solution Overview

Problem

Conventional capillary pumps in measurement chips face limitations in increasing pump capacity without enlarging the planar shape, leading to clogging issues due to narrow channels and impurities in sample solutions.

Innovation Solution

The design features pillars in a recess that do not contact the substrates, forming a gap to increase pump capacity and prevent clogging by allowing impurities to pass through, with pumps formed between substrates to enhance suction force without enlarging the planar dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the pump capacity is increased by enlarging the capillary pump structure, then the suction force and sample solution handling capability are improved, but the planar shape of the measurement chip becomes larger

Engineering Contradiction:
Improvepump capacityVSAvoidplanar shape of measurement chip
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The invention transitions from two-dimensional planar expansion to three-dimensional vertical stacking by forming multiple capillary pumps between stacked substrates. This allows increasing pump capacity through the thickness dimension rather than enlarging the chip footprint, resolving the contradiction between pump capacity and planar area.

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

2Productivity

If the fluidic channel is made narrow to transfer small amount of sample solution, then the sample solution transfer efficiency is improved, but the channel becomes prone to clogging by impurities

Engineering Contradiction:
Improvesample solution transfer efficiencyVSAvoidclogging resistance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention divides the fluidic channel into multiple segments by stacking substrates with multiple capillary pumps. This segmentation creates multiple parallel flow paths, allowing sample solution to be distributed across several channels, reducing the burden on individual narrow channels while maintaining transfer efficiency and reducing clogging risk.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies different structural characteristics to different regions: narrow channels for efficient sample transfer in measurement areas, and larger gaps between pillars in pump regions to prevent clogging. This local differentiation of channel dimensions optimizes both transfer efficiency and clogging resistance in respective functional zones.

Inventive Principle:
Principle #3Local quality

3Device complexity

If conventional paper chromatography methods are used for simple measurement, then the cost and complexity are reduced, but the ability to perform complicated chemical analysis is limited

Engineering Contradiction:
Improvemeasurement system complexityVSAvoidchemical analysis capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The invention creates a multi-functional measurement chip that integrates sample solution transfer, pumping, and measurement capabilities in a single device. The chip can handle various sample types and perform different chemical analyses by configuring multiple capillary pumps and fluidic channels, providing versatility while maintaining relatively simple structure through standardized substrate stacking.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 effectively increases pump capacity and ensures stable operation by preventing clogging, allowing for efficient handling of sample solutions with impurities without increasing the chip's size.

Implementation Method 1

a capillary pump for sucking it, and a measurement fluidic channel formed between the inlet port and the capillary pump. The capillary pump is formed from a cavity containing a plurality of pillars which connect the ceiling and bottom. The pillars have an interval enough to cause capillary action.

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

a pump which is connected to the other end of the fluidic channel and sucks, by the surface tension, a liquid that has reached the pump through the fluidic channel

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentEP2226623B1Flow cell
Publication Date: 2014.06.18 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP2226623B1 patent drawingFigure 1~2
  • EP2226623B1 patent drawingFigure 3~4
  • EP2226623B1 patent drawingFigure 5A~5B

AI summary

Ends (134a-1) of projections (134a) do not contact a first substrate (11), forming a gap between the ends (134a-1) and the first substrate (11). The internal capacity of a suction pump (17) can be increased by an amount by which the projections (134a) are shortened, compared to a conventional structure in which pillars are formed to connect the ceiling and bottom of the cavity of a capillary pump. The capacity of the suction pump (17) can be increased without enlarging the planar shape. Further, the ends (134a-1) of the projections (134a) do not contact the first substrate (11), forming a gap between them. An impurity can pass through the gap, and clogging of the inside of the suction pump (17) with the impurity can be prevented, realizing a stable operation.