Photonic Crystal Fiber Optical Trap for Multi-Particle Trapping

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Solution Overview

Problem

Existing optical trapping technologies face challenges in simultaneously trapping multiple particles of different types and wavelengths without interference effects, and in efficiently integrating photonic crystal fibers into microfluidic systems due to issues like fluid infiltration and alignment.

Innovation Solution

A system utilizing two or more photonic crystal fibers with counter-propagating outputs, capable of supporting multiple wavelengths, and a method to form an end cap using biocompatible silicon elastomer to prevent fluid infiltration, allowing for interference-free trapping and transport of particles using white light and multiple wavelengths, and integration into microfluidic chips.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional optical fibers are used for optical trapping, then the system is simple and easy to manufacture, but multiple wavelengths cannot be supported simultaneously and interference effects occur when trapping multiple particles

Engineering Contradiction:
Improvemulti-wavelength supportVSAvoidfiber structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the fundamental optical parameters of the fiber by transitioning from conventional solid-core fibers to photonic crystal fibers with hollow cores. This parameter change enables simultaneous support for multiple wavelengths including white light, while the photonic bandgap structure prevents interference effects by confining light in the hollow core region.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite fiber结构设计, combining photonic crystal lattice structures with hollow core regions. This composite approach creates fibers that can guide multiple wavelengths simultaneously through photonic bandgap effects, enabling versatile multi-wavelength trapping without interference.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If photonic crystal fibers are used for optical trapping, then multiple wavelengths and particles can be trapped simultaneously without interference, but fluid infiltration into the hollow core and alignment difficulties occur

Engineering Contradiction:
Improvemulti-particle trapping capabilityVSAvoidfluid infiltration resistance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent extracts the core functionality needed for optical trapping (light guidance) while removing the problematic hollow core exposure to fluids. By using photonic crystal fibers with controlled hollow core regions that are sealed or protected at the output end, the system maintains multi-wavelength trapping capability while preventing fluid infiltration that would compromise reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces intermediary structures such as sealing layers or protective coatings at the fiber output ends. These intermediaries allow the photonic crystal fiber to maintain its light-guiding properties while preventing direct contact between the hollow core and external fluids, thus solving the fluid infiltration problem.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Force

If tightly focused light is used for optical trapping, then strong trapping force is achieved, but the capture range is limited and trapping and imaging cannot be decoupled

Engineering Contradiction:
Improvetrapping forceVSAvoidcapture range
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The patent segments the optical system into separate functional components: the photonic crystal fiber delivers the trapping light, while separate imaging objectives capture images. This segmentation allows the trapping beam to be optimized for force while the imaging system is optimized for capture range, enabling both strong trapping force and large capture range simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent makes the photonic crystal fiber the universal light delivery mechanism that can support multiple wavelengths and trapping configurations. The fiber's ability to guide white light and multiple laser wavelengths simultaneously provides multi-functionality, enabling both strong trapping force through wavelength optimization and large capture range through extended wavelength coverage.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables simultaneous trapping of multiple particles without interference, provides a long-range optical conveyor belt for selective particle transport, and facilitates efficient integration of photonic crystal fibers into microfluidic systems, enhancing trapping capabilities and spectroscopic applications.

Implementation Method 1

Categories of PCF include photonic bandgap fibres that confine light by band gap effects

Methodology Applied
Scientific EffectPhotonic bandgap effects: Photonic Crystal

Implementation Method 2

An optical trap can be formed using two counter propagating diverging beams due to a combination of optical refraction and optical scattering

Methodology Applied
Scientific EffectOptical refraction: Refraction

Implementation Method 3

An optical trap can be formed using two counter propagating diverging beams due to a combination of optical refraction and optical scattering

Methodology Applied
Scientific EffectOptical scattering: Scattering

Implementation Method 4

multiple particles of different types can be trapped simultaneously, without suffering from interference effects

Methodology Applied
Scientific EffectInterference effects: Interference

Data Source

PatentEP2297600B1Optical trap
Publication Date: 2015.04.15 UNIV COURT OF THE UNIV OF ST ANDREWS
  • EP2297600B1 patent drawingFigure 1
  • EP2297600B1 patent drawingFigure 2
  • EP2297600B1 patent drawingFigure 3

AI summary

A system for forming an optical trap comprising two or more photonic crystal fibers (PCFs) and at least one source of radiation for inputting radiation to the photonic crystal fibers, the fibres being operable to provide counter-propagating outputs for forming the optical trap.