Microfluidic Sensor Manufacturing with Conductive Ink Electrodes
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Solution Overview
Problem
Current microfluidic sensors face challenges in efficiently interrogating particles suspended in fluids, particularly in accurately detecting and analyzing particles in a cost-effective and disposable manner, with limitations in sensitivity and repeatability.
Innovation Solution
A method for manufacturing microfluidic sensors involves applying electrically conductive ink onto thin film substrates to form electrodes and channel layers, creating an interrogation tunnel for fluid communication, and configuring electrodes to permit electrical interrogation of particles, enabling detection of particle presence and characteristics through impedance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional microfluidic sensors are used for particle detection, then particle interrogation capability is provided, but manufacturing cost is high and disposability is limited
Solution Approach 1:
The sensor is divided into multiple functional layers (substrate layer, channel layer, cap layer) that can be manufactured separately and assembled. This segmentation enables cost-effective manufacturing of disposable sensors while maintaining detection accuracy through specialized design of each layer.
Solution Approach 2:
The patent implements a complete disposable sensor system where the entire microfluidic device including substrate, channels, and electrodes is designed as a single-use component. This eliminates contamination risks and reduces manufacturing costs through simplified material selection and assembly processes.
2Measurement precision
If complex electrode configurations are implemented for improved particle interrogation, then detection sensitivity increases, but device complexity increases
Solution Approach 1:
The electrode configuration is extracted and integrated directly into the substrate layer, eliminating the need for separate electrode assemblies. This simplifies the overall device structure while maintaining detection sensitivity through optimized electrode geometry and positioning within the substrate.
Solution Approach 2:
Multiple functional elements (substrate, electrode support, electrode mounting) are merged into a single integrated substrate layer. This reduces device complexity by eliminating separate components while preserving particle interrogation capability through carefully designed electrode patterns.
3Ease of manufacture
If thin film substrates are used for sensor manufacturing, then device portability and disposability improve, but manufacturing precision requirements increase
Solution Approach 1:
Electrodes are fabricated and positioned on the substrate layer before assembling the complete sensor device. This preliminary action allows for precise electrode placement using standard printing techniques while maintaining the benefits of thin-film construction for portability and disposability.
Solution Approach 2:
The substrate thickness and material properties are optimized to balance manufacturing precision requirements with portability benefits. By selecting appropriate thin-film parameters (thickness, material, flexibility), the device achieves both ease of manufacture as disposable components and sufficient structural integrity for accurate particle detection.
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 method enables low-cost, disposable sensors for efficient particle detection and analysis, providing rapid and accurate results suitable for point-of-care testing and laboratory research, with improved signal fidelity and reduced noise.
Implementation Method 1
The principle of particles causing a change in electric impedance as they occlude a portion of an aperture between electrically charged vessels is disclosed in U.S. Pat. No. 2,656,508 to W. H, Coulter.
Implementation Method 2
The ability of certain particles to emit radiation at a different frequency than an applied excitation frequency is commonly known as Stokes-shift.
Data Source
AI summary
A method to manufacture microfluidic sensors 100, 100′, 132, 280, 380, includes stacking a plurality of layers of material to form at least a first cap layer 102, a first channel layer 104, an interrogation layer 106, and a second channel layer 108. During assembly, ribbon sections of substrate layers are sandwiched to cooperatively align elements through-the-thickness of the sandwich. Individual sensors are then removed from the sandwich ribbon 504. A componentizing step includes forming one or more element for successive sensors spaced along the axial length of a ribbon of substrate material. Certain elements include electrically conductive patterned structures 250 printed onto a substrate using conductive ink and a printing process. Sometimes, the printing process places material in operable position to conduct electricity through the thickness of at least one ribbon. Other elements may include channels 112, 116; tunnels 114, and vias 260, 268.