Particle Characterization via Electrohydrodynamic Flow Control
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Solution Overview
Problem
Existing methods for characterizing and counting particles, such as cells and droplets, are limited by 'Fixed-Pattern-Noise' and require pumps or liquid flows for accurate positioning, which complicates reliable detection and classification.
Innovation Solution
The use of non-uniform, time-variable force fields, such as dielectrophoresis, electrophoresis, or electro-hydrodynamic motions, combined with integrated optical and impedance sensors, allows for precise manipulation and characterization of particles without the need for pumps or liquid flows, making the system insensitive to spatial variations and 'Fixed-Pattern-Noise'.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pumps or liquid flows are used for accurate positioning of particles, then positioning precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces mechanical pumping systems with electrohydrodynamic flows generated by electrode arrays. The electrohydrodynamic forces create liquid flows that transport particles to predetermined positions without requiring external pumps, thereby maintaining positioning precision while reducing device complexity
Solution Approach 2:
The patent uses time-varying voltage parameters applied to electrode arrays to dynamically control electrohydrodynamic flows. By changing voltage magnitude and temporal patterns, the system achieves accurate particle positioning through parameter modulation rather than mechanical actuation
2Difficulty of detecting and measuring
If fixed spatial sensor arrays are used for particle detection, then detection capability is provided, but Fixed-Pattern-Noise limits reliability
Solution Approach 1:
The patent employs time-varying voltage patterns applied to electrode arrays that dynamically modulate the detection environment. This temporal variation allows differentiation between static Fixed-Pattern-Noise and dynamic particle signals, improving detection reliability by enabling noise cancellation through temporal filtering
Solution Approach 2:
The patent uses periodic voltage excitation patterns that create time-varying electrohydrodynamic flows and detection fields. By analyzing particle responses at specific frequencies and using periodic modulation, the system distinguishes particle signals from static sensor noise patterns
3Ease of operation
If spatial variations of illumination or conductivity are present, then sensor operation is enabled, but measurement accuracy deteriorates
Solution Approach 1:
The patent implements feedback mechanisms where sensor readings from multiple electrodes are continuously monitored and used to adjust voltage patterns. This feedback enables real-time compensation for spatial variations in illumination or conductivity, maintaining measurement accuracy while preserving sensor operation capability
Solution Approach 2:
The patent compensates for spatial variations by dynamically adjusting voltage parameters across different electrode positions. By modifying local voltage magnitudes and phases in response to detected variations, the system corrects measurement errors caused by non-uniform illumination or conductivity
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 approach enables accurate characterization and classification of particles with improved precision and information extraction, including movement speed, which aids in differentiating particle types, and is immune to illumination variations and noise.
Implementation Method 1
The force used for trapping in suspension the particles is the negative dielectrophoresis
Implementation Method 2
The use of non-uniform, time-variable force fields, such as dielectrophoresis, electrophoresis
Implementation Method 3
A further force for the manipulation of particles is the viscous friction force generated by electro-hydrodynamic (EHD) flows
Implementation Method 4
The use of non-uniform, time-variable force fields, such as dielectrophoresis, electrophoresis, or electro-hydrodynamic motions, combined with integrated optical and impedance sensors
Implementation Method 5
combined with integrated optical and impedance sensors
Data Source
Figure 1~3(c)
Figure 4~5
Figure 6~7
AI summary
The present invention relates to an apparatus for the characterization and/or the counting of particles by means of non uniform, time variable force fields and integrated optical or impedance meter sensors. The force fields can be of positive or negative dielectrophoresis, electrophoresis or electro-hydrodynamic motions, characterized by a set of stable equilibrium points for the particles (solid, liquid or gaseous); the same apparatus is suitable for the manipulation of droplets (liquid particles) by exploiting effects known to the international scientific community with the name of Electro-wetting on dielectric. The aim of the present invention is to act on the control of the position of each particle which is present in the sample, for the purpose of displacing such particles in a deterministic or statistical way, in order to detect their presence with the integrated optical or impedance meter sensors and/or characterize their type, for the purpose of counting or manipulating them in an efficient way.