Plasmonic Substrate Particle Transport via Electrothermal Vortices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional plasmonic trapping methods face limitations in efficiently trapping and manipulating submicron and nanoscale particles due to local heat generation, which causes thermophoresis and boiling, and are hindered by short-range interactions of near-field electromagnetic forces, making it difficult to transport particles over long distances for applications like lab-on-a-chip biosensing.
Innovation Solution
Harnessing the collective heating effect of plasmonic nanostructures combined with Rapid Electrokinetic Patterning (REP) using a tightly focused laser beam to generate electrothermal vortices that rapidly transport particles across a plasmonic substrate, overcoming the limitations of local heat generation and enhancing particle manipulation and sorting efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional plasmonic trapping is used to trap submicron and nanoscale particles, then local field enhancement and optical gradient forces are generated, but local heat generation causes thermophoresis and boiling which obscures the trapping process
Solution Approach 1:
The patent converts the harmful local heating effect into a beneficial electrothermal force by applying an external AC electric field. The heat generated by plasmonic nanostructures, which previously caused thermophoresis and boiling, is now utilized to create electrothermal vortices that actively transport particles toward the nanostructures for trapping and concentration.
2Volume of moving object
If near-field electromagnetic forces are used for particle trapping, then sub-wavelength electromagnetic field confinement is achieved, but the force field can only be felt by objects after they have diffused several nanometers close to the resonant nanostructure where the interaction is inherently slow
Solution Approach 1:
The patent introduces electrothermal vortices as an intermediary mechanism between the plasmonic nanostructures and the particles. Instead of relying solely on direct near-field electromagnetic interactions that require particles to diffuse close to the nanostructures, the electrothermal vortices create fluid flow that actively transports particles toward the trapping sites, significantly increasing transport speed.
3Quantity of substance
If plasmonic nanostructures are used for particle manipulation, then high photonic density of states is generated, but the separation between nanostructures must be small for near-field coupling which limits long-distance particle transport
Solution Approach 1:
The patent replaces the reliance on near-field electromagnetic coupling with electrothermal fluid dynamics. By applying an external AC electric field to generate electrothermal vortices, the system achieves long-distance particle transport through fluid flow rather than through near-field coupling between closely spaced nanostructures, allowing greater separation distances while maintaining 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
This approach enables high-throughput, dynamic manipulation and sorting of micro and nanoscale particles with reduced laser power, achieving rapid particle transport and concentration on a plasmonic substrate, improving the efficiency of lab-on-a-chip applications and biosensing by leveraging the enhanced photonic density of states.
Implementation Method 1
the local field enhancement around a local localized surface plasmon resonance (LSPR) supporting nanostructure, generated via resonant coupling of incident photons with free electrons on metallic nanostructures
Implementation Method 2
the excitation of localized surface plasmonic resonance and hence local field enhancement is also accompanied by resonant light absorption, which results in local heat generation
Implementation Method 3
a non-uniform to generate a thermal gradient, wherein the thermal gradient is configured to generate the electrothermal force within the fluidic medium
Implementation Method 4
This local heating effect has been seen as an obstacle to stable trapping of particles on a plasmonic substrate because of heating induced thermophoresis
Implementation Method 5
a top portion that includes an electrode that is configured to receive a laser beam that heats the electrode
Implementation Method 6
an electrode that is configured to receive a laser beam that heats the electrode
Implementation Method 7
Rapid Electrokinetic Patterning (REP) using a tightly focused laser beam to generate electrothermal vortices that rapidly transport particles
Implementation Method 8
generate electrothermal vortices that rapidly transport particles across a plasmonic substrate
Data Source
AI summary
The present disclosure relates generally to plasmonic substrates and specifically to high-throughput trapping of particles on a plasmonic substrate.