Particle Sorting Charge Control for Non-Uniform Droplets

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Solution Overview

Problem

Particle sorting apparatuses face instability in droplet direction when particles of different sizes coexist in a sample fluid, leading to reduced sorting accuracy and efficiency.

Innovation Solution

A particle sorting apparatus that adjusts the charge amount based on particle size using a charge control section, which determines the appropriate charge level by detecting forward-scattered light intensity, ensuring stable droplet direction and efficient sorting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a flow cell or microchip is vibrated to form droplets for particle sorting, then sorting function is achieved, but droplet traveling direction becomes unstable when particles of different sizes coexist, reducing sorting accuracy

Engineering Contradiction:
Improvesorting functionVSAvoidsorting accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent changes the charge amount parameter based on particle size. Larger particles receive higher charge amounts while smaller particles receive lower charge amounts. This parameter adjustment compensates for the instability in droplet traveling direction caused by mixed particle sizes, allowing accurate sorting to be maintained across different particle types.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where the charge amount is adjusted according to the detected particle size. The system measures particle properties, determines the appropriate charge level, and applies it dynamically. This closed-loop control ensures that droplet direction remains stable and sorting accuracy is maintained even when different sized particles are present in the sample.

Inventive Principle:
Principle #23Feedback

2Device complexity

If fixed charge amount is applied to all droplets, then charging process is simple, but droplet direction control becomes unstable for non-uniform particles

Engineering Contradiction:
Improvecharging processVSAvoiddroplet direction stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent transitions from a static charging system to a dynamic one where the charge amount varies based on particle characteristics. Instead of applying a fixed charge to all droplets, the system dynamically adjusts the charge level according to the specific particle size detected in each droplet. This dynamic approach maintains reliable droplet direction control while adapting to non-uniform particles in the sample.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If charge amount is increased for larger particles to maintain direction control, then sorting of large particles improves, but sorting efficiency for smaller particles decreases

Engineering Contradiction:
Improvesorting precision for large particlesVSAvoidsorting efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies the principle of local quality by tailoring the charge amount to the specific particle size in each droplet. Rather than using a uniform charge level that would compromise either large or small particle sorting, the system locally optimizes the charge for each particle type. This ensures that both large and small particles are sorted with high precision and efficiency simultaneously.

Inventive Principle:
Principle #3Local quality

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 apparatus stabilizes the traveling direction of droplets regardless of particle size, enabling efficient sorting of non-uniform particles by adjusting the charge amount according to their size, thereby improving sorting accuracy and efficiency.

Implementation Method 1

a flow cell or a microchip is vibrated by a vibration device or the like to form droplets of a fluid discharged from the flow channel

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

After the droplets separated from the fluid is imparted with charges of plus (+) and minus (-)

Methodology Applied
Scientific EffectElectrostatic charging: Electrostatics

Implementation Method 3

a traveling direction thereof is changed by a deflection plate or the like so that the droplets are recovered in a predetermined vessel

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 4

an optical measurement method that uses flow cytometry (flow cytometer) has been used for analyzing biologically-relevant micro-particles... detects and analyzes fluorescence and scattered light emitted from the individual micro-particles

Methodology Applied
Scientific EffectFlow cytometry optical detection: Scattering

Data Source

PatentEP3035030B1Particle fractionation device, particle fractionation method, and program
Publication Date: 2019.07.10 SONY GROUP CORP
  • EP3035030B1 patent drawingFigure 1
  • EP3035030B1 patent drawingFigure 2
  • EP3035030B1 patent drawingFigure 3

AI summary

[Object] To provide a particle sorting apparatus, a particle sorting method, and a program that are capable of efficiently sorting particles even when sizes of particles to be sorted are not uniform. [Solving Means] A particle sorting apparatus includes a charge section that imparts charges to at least a part of droplets discharged from an orifice from which a fluid stream is generated, and a charge control section that adjusts a charge amount to be imparted to the droplets by the charge section. Further, the charge control section is structured to adjust the charge amount according to sizes of particles included in the droplets.