Terahertz Micro-Fluidic Sensor Resonance Absorption
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Solution Overview
Problem
Current terahertz micro-fluidic sensors face limitations in sensitivity due to the degree of superposition between evanescent waves and liquid samples, which restricts the detection sensitivity.
Innovation Solution
A high-sensitivity terahertz micro-fluidic channel sensor is developed, featuring a metal plane reflector, a micro-fluidic channel, and a metal microstructure layer, forming a composite structure that achieves spatial superposition and resonance absorption, enhancing detection sensitivity by localizing the electromagnetic field within the micro-fluidic channel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If evanescent wave coupling method is used for terahertz micro-fluidic sensing, then the sensor can detect liquid samples, but the sensitivity is limited due to insufficient superposition between evanescent waves and liquid samples
Solution Approach 1:
The patent employs resonant oscillation of the microstructure at terahertz frequency to enhance the interaction between electromagnetic waves and liquid samples. The resonant structure creates strong local electromagnetic fields that significantly improve the superposition degree between evanescent waves and liquid samples, thereby enhancing detection sensitivity beyond conventional evanescent wave coupling methods.
Solution Approach 2:
The patent optimizes geometric parameters of the microstructure (such as dimensions, shape, and configuration) to achieve resonant conditions at specific terahertz frequencies. By adjusting these parameters, the resonant frequency and quality factor are optimized to maximize the superposition between electromagnetic fields and liquid samples, directly improving measurement precision.
2Measurement precision
If conventional terahertz sensing methods are used, then the sensor structure is relatively simple, but the absorption rate and sensitivity remain below 95%
Solution Approach 1:
The patent employs a composite structure consisting of a metal plane reflector, a micro-fluidic channel, and a metal microstructure layer. This composite configuration creates a resonant cavity that traps electromagnetic energy within the liquid sample region, achieving over 95% absorption at resonant frequencies. The combination of different materials and structural elements works synergistically to enhance the sensing performance.
Solution Approach 2:
The micro-fluidic channel is nested between the metal plane reflector and the metal microstructure layer, forming a confined resonant cavity. This nested structure ensures that electromagnetic fields are localized within the liquid sample region, maximizing the interaction between the fields and the analyte while achieving high absorption rates.
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
The sensor achieves over 95% absorption at resonance frequency, allowing for highly sensitive detection of refractive index changes with a sensitivity of 3.44 THz/RIU, significantly improving upon existing technologies.
Implementation Method 1
a composite structure mainly formed of the metal microstructure layer, the liquid to be tested and the metal plane reflector shows, in the terahertz band, good absorption properties due to resonance
Implementation Method 2
realizes spatial superposition between electromagnetic-field localization and liquid to be tested in the micro-fluidic channel at a resonance frequency
Implementation Method 3
sense by perceiving change in the refractive index of samples to be tested
Implementation Method 4
detecting change in optical transmission properties resulted from the coupling between evanescent waves on the surface of the micro-strip lines and the liquid sample
Data Source
AI summary
A high-sensitivity terahertz micro-fluidic channel sensor and a preparation method thereof. The sensor includes a substrate and a cover layer, respectively provided with a metal plane reflector and a metal microstructure layer; a micro-fluidic channel is formed between the metal plane reflector and the metal microstructure layer; and when the micro-fluidic channel tests liquid, a composite structure formed of the metal microstructure layer, the test liquid and the metal plane reflector shows good absorption properties. The method includes forming a metal plane reflector and a metal microstructure layer on a substrate and a cover layer, respectively; fixedly connecting the substrate to the cover layer, and forming a closed micro-fluidic channel between the substrate and the cover layer; and forming a through via, communicated to the micro-fluidic channel, on the substrate and/or the cover layer, to form a flow channel for transferring liquid to be tested to or from the sensor.