Acousto-Optic Particle Sorting via Reconfigurable Optical Landscape

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Solution Overview

Problem

Existing optical sorting techniques face limitations in efficiently separating microscopic particles like cells and colloidal matter due to slow processing, limited pore sizes, and impracticality of discrete optical lattices, as well as inefficiencies in holographic and interferometric methods.

Innovation Solution

The use of an acousto-optic device to rapidly reconfigure an optical landscape with controlled laser beam properties, allowing for dynamic and high-power sorting by creating a gradient force that acts against fluid flow, enabling efficient separation of particles based on size and refractive index.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If gel electrophoresis is used for particle separation, then separation effectiveness is improved, but processing speed deteriorates and microscopic particle separation becomes difficult

Engineering Contradiction:
Improveseparation effectivenessVSAvoidprocessing speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical gel matrix system with an optical field-based separation system. Instead of using physical gels with fixed pore sizes that limit both speed and microscopic particle separation, the invention uses optically induced forces (optical tweezers and gradient forces) to manipulate particles in free-flowing fluid, eliminating the mechanical constraints of gel electrophoresis while maintaining separation effectiveness.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces dynamic control of optical fields to enable rapid reconfiguration of separation parameters. The optical landscape can be dynamically adjusted in real-time to optimize separation for different particle sizes and properties, unlike static gel systems. This dynamic control allows the system to adapt processing conditions on-the-fly, improving both speed and versatility for microscopic particle separation.

Inventive Principle:
Principle #15Dynamics

2Productivity

If two-dimensional asymmetric artificial gels are used, then continuous operation is enabled, but sorting based on diffusion becomes impractically slow at microscopic scale

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidsorting speed
Core Design Contradiction:
ProductivityVSSpeed

Solution Approach 1:

The patent replaces diffusion-based sorting mechanisms with optically driven sorting. Instead of relying on Brownian motion and diffusion through gel matrices (which is inherently slow at microscopic scales), the invention uses optical gradient forces and optical tweezers to actively transport and sort particles at much higher speeds while maintaining continuous operation capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If discrete optical traps are used, then flow direction control is improved, but deflection angle is limited to small angles

Engineering Contradiction:
Improveflow direction controlVSAvoiddeflection angle range
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent uses an array of discrete optical traps that can be independently controlled. By segmenting the optical field into multiple controllable zones, the system can guide particles through a sequence of traps with varying orientations, accumulating larger deflection angles through multiple small-angle deflections rather than requiring a single large-angle deflection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extends the sorting mechanism from two-dimensional lattice structures to three-dimensional optical landscapes. This allows particles to be manipulated through multiple spatial dimensions, enabling larger effective deflection angles by combining deflections in different directions and planes, thus overcoming the small-angle limitation of planar lattice structures.

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

4Adaptability or versatility

If holographic and interferometric methods are used, then optical sorting capability is achieved, but beam quality and efficiency deteriorate and system complexity increases

Engineering Contradiction:
Improveoptical sorting capabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts and isolates the essential function of optical sorting from complex holographic and interferometric systems. By using direct optical trapping and gradient force mechanisms without requiring beam splitting components or sophisticated holographic algorithms, the invention maintains optical sorting capability while dramatically reducing system complexity and improving beam quality and efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

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 rapid and efficient sorting of polydisperse mixtures with near-100% efficiency by creating a reconfigurable optical landscape that can be tailored for different applications, enhancing sorting speed and precision, especially in lab-on-chip environments.

Implementation Method 1

an acousto-optic device to modulate a laser and thereby create an optical landscape

Methodology Applied
Scientific EffectAcousto-optic effect: Acousto-optic Effect

Implementation Method 2

creating a gradient force that acts against fluid flow, enabling efficient separation of particles based on size and refractive index

Methodology Applied
Scientific EffectOptical gradient force: Optical Tweezers

Data Source

PatentEP2064708B1Optical sorting
Publication Date: 2014.11.12 UNIV COURT OF THE UNIV OF ST ANDREWS
  • EP2064708B1 patent drawingFigure 1
  • EP2064708B1 patent drawingFigure 2a~2b
  • EP2064708B1 patent drawingFigure 3(a)

AI summary

A method for sorting particles in a fluid. The method involves generating an optical landscape using an acousto-optic device. Preferably, the optical landscape is arranged to sort particles based on size or refractive index or shape.