Well Array Filter With Multi-Hole Well Bottoms for Single-Cell Capture

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Solution Overview

Problem

Existing well array filters face challenges in achieving high single cell capture rates while maintaining liquid permeability, as increasing well opening diameter reduces the number of wells per unit area and decreasing it leads to reduced liquid permeability and increased risk of cells passing through the through-holes.

Innovation Solution

The well array filter design includes a flat filter body with open wells separated by partition walls, featuring two or more through-holes in the well bottom portion, with specific dimensions and positional relationships to ensure high single cell capture rates and stable liquid permeability, using materials like MPC polymer to restrict cell adhesion and enhance handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the opening diameter of the well is increased to facilitate cell culture and capillary handling, then the ease of operation is improved, but the number of wells per unit area decreases, reducing productivity

Engineering Contradiction:
Improveease of operationVSAvoidnumber of wells per unit area
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The well bottom portion is segmented into multiple through-holes (two or more) instead of a single through-hole. This segmentation allows the filter to maintain smaller well openings for higher density while providing multiple escape paths for cells, resolving the contradiction between well size and capture efficiency

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The through-holes are positioned specifically at the bottom portion of the wells with controlled dimensions (minimum width 1-3.5 μm). This local optimization of the bottom structure allows selective cell passage while maintaining the overall well integrity and appropriate size for handling, addressing the contradiction between well size and cell capture

Inventive Principle:
Principle #3Local quality

2Productivity

If the opening diameter of the well is decreased to increase the number of wells per unit area, then the productivity is improved, but the liquid permeability deteriorates and the risk of cells passing through through-holes increases

Engineering Contradiction:
Improvenumber of wells per unit areaVSAvoidliquid permeability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The well bottom portion is designed as a porous structure with multiple through-holes instead of a single opening. This porous configuration maintains adequate liquid permeability even when well openings are small, as the cumulative area of multiple small through-holes provides sufficient flow paths while preventing cell passage through the controlled hole dimensions

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The single through-hole is segmented into multiple smaller through-holes (two or more) at the well bottom. This segmentation increases the total surface area for liquid permeation while maintaining individual hole dimensions that prevent cell passage, thus improving reliability of liquid flow in high-density well arrays

Inventive Principle:
Principle #1Segmentation

3Reliability

If the number of through-holes is increased to improve liquid permeability, then the liquid permeability is improved, but the single cell rate decreases as cells may pass through multiple holes

Engineering Contradiction:
Improveliquid permeabilityVSAvoidsingle cell rate
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The dimensions of through-holes are precisely controlled within specific ranges (minimum width 1-3.5 μm) to match cell sizes. This parameter optimization ensures that while multiple through-holes provide sufficient liquid permeability, the controlled dimensions prevent cell passage through the holes, maintaining high single cell capture rates

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The through-holes are positioned specifically at the bottom portion of wells with controlled dimensions and spacing. This localized optimization ensures that the through-holes are small enough to prevent cell passage while providing adequate liquid flow paths, resolving the contradiction between permeability and single cell capture

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4620549A1Well array filter, particle alignment device, and particle capture method
Publication Date: 2025.09.24 TOKYO OHKA KOGYO CO LTD
  • EP4620549A1 patent drawingFigure 1~2
  • EP4620549A1 patent drawingFigure 3(a)~3(c)
  • EP4620549A1 patent drawingFigure 4(a)~4(c)

AI summary

In a well array filter (1), a plurality of wells (3) are formed in a filter body (2), the wells (3) adjacent to each other are separated by a well partition wall (6), two or more through-holes (8) are formed in a well bottom portion (4), the minimum width of the opening of the through-hole (8) is 1 µm or more and 3.5 µm or less, and the ratio of a total opening area of the through-hole is 0.5% or more and 3.5% or less. Assuming a minimum circumscribed circle (G1) that surrounds all of the through-holes (8) in each well bottom portion (4), when the center is moved to the center of each of the plurality of through-holes (8), all minimum circumscribed circles (G2) after movement at least partially overlap all of the plurality of through-holes (8).