Capillary Pump Unit With Stacked Through Portions

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Solution Overview

Problem

Existing capillary pump units for sample liquid transfer in microfluidic systems have limited pump capacity and are difficult to fabricate in small sizes with high aspect ratios, leading to challenges in efficiently flowing and measuring small sample volumes.

Innovation Solution

A capillary pump unit with a plurality of through portions on a flat-plate-shaped base allows for sample liquid transfer between opposing surfaces, enabling increased pump capacity in the height direction without expanding the plane area, and can be formed by stacking sheet-shaped bases to achieve a high aspect ratio and efficient space use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a flow channel is formed on a substrate and other components are provided on the same substrate, then a small amount of sample liquid can be transferred, but it is difficult to fabricate the device

Engineering Contradiction:
Improvesample liquid transfer amountVSAvoidfabrication difficulty
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The device is divided into a substrate and a separate capillary pump unit. The capillary pump unit is formed by stacking multiple sheet-shaped bases with through portions, separating the pumping function from the flow channel substrate. This segmentation enables independent fabrication of each component and simplifies the overall manufacturing process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The capillary pump unit utilizes the height direction (vertical dimension) by stacking sheet-shaped bases to increase pump capacity without expanding the plane area. This dimensional approach allows achieving high aspect ratio and efficient space utilization while maintaining compact device footprint.

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

2Quantity of substance

If separate parts such as a pump or a tube are provided in addition to the substrate constituting the flow channel, then sample liquid can be transferred under external pressure, but dead volume of the sample liquid increases, limiting use to a small amount of the sample liquid

Engineering Contradiction:
Improvesample liquid transfer amountVSAvoiddead volume
Core Design Contradiction:
Quantity of substanceVSLoss of substance

Solution Approach 1:

The capillary pump unit is integrated with the flow channel substrate to form a unified microfluidic system. The through portions in the stacked bases create compact pumping chambers that are directly connected to the flow channel, eliminating the need for separate external pumps and tubes. This integration minimizes dead volume and enables efficient use of small sample amounts.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If the capacity of the pump is increased to flow a greater amount of sample fluid, then measurement precision can be improved, but the device size increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddevice size
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The capillary pump unit increases pump capacity by stacking sheet-shaped bases in the vertical direction, utilizing the height dimension rather than expanding the planar footprint. This approach achieves high pump capacity and high aspect ratio while maintaining a compact device size suitable for portable applications.

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

Solution Approach 2:

The stacked sheet-shaped bases with through portions create a porous-like structure that provides multiple capillary channels for sample liquid flow. This structure increases the effective pump capacity and surface area for capillary action without proportionally increasing the overall device volume.

Inventive Principle:
Principle #31Porous materials

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 configuration allows for continuous flow of sample liquid, enhancing measurement precision and reliability while maintaining a compact, cost-effective design.

Implementation Method 1

a sample liquid is transferred from a first point to a second point by capillary force by the through portions

Methodology Applied
Scientific EffectCapillary force: Capillary Action

Data Source

PatentEP2230504B1Capillary pump unit and flow cell
Publication Date: 2013.04.24 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP2230504B1 patent drawingFigure 1
  • EP2230504B1 patent drawingFigure 2
  • EP2230504B1 patent drawingFigure 3

AI summary

In a capillary pump unit, a capillary pump including a plurality of through portions making a first point and a second point of an approximately flat-plate-shaped base communicable with each other are formed in the base, and a sample liquid is transferred from the first point to the second point by capillary force by the through portions.