Plasmonic Pumping via Thermoresponsive Polymer Volume Phase Transition
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Solution Overview
Problem
Existing plasmonic sensors require external pumping mechanisms, which are diffusion-limited and inefficient, leading to longer analysis times and reduced sensitivity due to depletion zones and 'flow-over' modes.
Innovation Solution
A pumping system comprising a substrate with a thermoresponsive polymer and a film, where a heat source generates heat to induce temperature variations above and below the volume phase transition temperature, creating pressure variations to actively transport analytes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If external pumping mechanisms are used to transport analytes, then analyte delivery to detection zone is achieved, but analysis time increases and sensitivity decreases due to diffusion limitations and depletion zones
Solution Approach 1:
The patent replaces external mechanical pumping mechanisms with an integrated photothermal pumping system. The plasmonic nanostructures convert incident light into localized thermal energy, which directly drives analyte transport through thermophoresis and thermal convection within the sensor structure itself, eliminating the need for separate mechanical pumps and reducing analysis time.
Solution Approach 2:
The patent merges the pumping function with the sensing structure by integrating photothermal actuators directly into the sensor platform. The same plasmonic nanostructures that enable optical sensing also generate thermal fields for active analyte transport, combining multiple functions into a single integrated system that improves both speed and sensitivity.
2Productivity
If external pumping mechanisms are used, then analyte transport is achieved, but sensitivity is reduced due to depletion zones formation
Solution Approach 1:
The patent replaces external mechanical pumping with photothermal-driven transport that creates localized thermal gradients directly at the sensing interface. This approach generates controlled fluid flow patterns that enhance analyte accumulation at the detection zone without creating depletion zones, thereby maintaining high sensitivity while achieving efficient transport.
Solution Approach 2:
The patent creates localized thermal fields through plasmonic nanostructures that are spatially confined to the sensing region. This localized heating generates targeted thermal convection and thermophoretic forces only where needed, enhancing analyte delivery to the detection zone without disrupting the overall analyte distribution and preventing depletion zone formation.
3Measurement precision
If traditional flow-over mode is used in plasmonic sensors, then analyte detection is achieved, but analysis time increases due to diffusion-limited transport
Solution Approach 1:
The patent substitutes passive diffusion-based flow-over mode with active photothermal pumping. The integrated photothermal actuators generate thermal fields that drive analyte transport through thermophoresis and thermal convection, replacing reliance on slow diffusion processes with faster thermally-driven transport mechanisms while maintaining detection precision.
Solution Approach 2:
The patent employs periodic modulation of the incident light intensity to the plasmonic nanostructures, creating oscillating thermal fields that enhance analyte transport through periodic thermal convection currents. This periodic thermal action accelerates analyte delivery to the detection zone compared to static flow-over modes, reducing analysis time while maintaining detection sensitivity.
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 system eliminates the need for external pumping, enhances analyte transport efficiency, reduces analysis time, and increases sensitivity by allowing faster and more precise delivery of analytes to the detection zone.
Implementation Method 1
a heat source is provided so that heat can be generated in the film
Implementation Method 2
the thermoresponsive polymer can experience temperatures above and below the volume phase transition temperature, so that a controlled volume reduction and volume increase of the thermoresponsive polymer is possible
Implementation Method 3
LSPR occurs when the dimensions of a metallic nanostructure are smaller than the wavelength of incident light, resulting in collective but non-propagating oscillations of surface electrons in the metallic nanostructure. LSPR depends strongly on the refractive index of the surrounding medium and forms the basis for colorimetric plasmonic sensors. LSPR also concentrates the incident electromagnetic (EM) field around the nanostructure.
Implementation Method 4
SPPs are the propagating charge oscillations on the surface of thin metal films. SPPs cannot be excited by radiation from free space, but require momentum matching, e.g., periodicity in a nanostructure, to achieve resonance excitation. SPPs are modulated by the refractive index of the surrounding medium and transform the sensor signal. The evanescent EM field of SPP decays with a longer length (usually about 200 nm) than LSPR, so SPP can be modulated by changes at a greater distance from the nanostructure surface.
Data Source
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AI summary
In a first aspect, the invention relates to a pumping system for transporting an analyte in a medium. The pumping systems comprises a substrate, wherein the substrate is positioned in a medium and a thermoresponsive polymer is disposed on the substrate. Furthermore, a film is disposed on the thermoresponsive polymer. The pumping system also comprises a heat source so that heat can be generated in the film. Through this, the medium and the thermoresponsive polymer also experience a thermal effect. Through the heat source, the thermoresponsive polymer can experience temperatures above and below the volume phase transition temperature, so that a controlled volume reduction and volume increase of the thermoresponsive polymer is possible. By reducing the volume of the thermoresponsive polymer, a pressure reduction can be achieved, and by increasing the volume, a pressure increase can be achieved in the medium and a pumping effect can be achieved through the pressure variation. Furthermore, the invention relates to a sensor and a method for transporting and/or detecting an analyte in a medium.