Valveless Flow Conduit System for Biochemical Sensors
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Solution Overview
Problem
Existing label-free biochemical sensors face challenges in achieving fast fluid transitions, high sensitivity, large measuring range, high readout speed, low costs, simple device handling, and low maintenance requirements, particularly due to complexities and costs associated with integrated microvalves and alignment issues in current microfluidic systems.
Innovation Solution
A flow conduit system with valveless junctions and controlled injection conduits allows for fast fluid transitions by minimizing the dead volume between the flow cell and valveless junctions, eliminating the need for valves near the sensing area, thus reducing costs and mechanical artifacts, and enabling undiluted fluid injection with precise control over fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If integrated microvalves are used to control fluid flow near the sensing area, then fluid flow control is improved, but device complexity and manufacturing costs increase
Solution Approach 1:
The patent removes valves from the immediate vicinity of the sensing area, extracting the fluid control function to a remote location. The flow cell is designed without integrated microvalves near the sensing zones, eliminating the complexity and cost associated with precise valve integration while maintaining fluid control capability through a simplified conduit system.
Solution Approach 2:
The fluidic system is segmented into distinct functional zones: a flow cell containing sensing areas where fluid-sample interaction occurs, and a separate fluid control system with valves positioned remotely. This segmentation allows the sensing area to remain simple and valve-free while maintaining controlled fluid delivery through the segmented conduit architecture.
2Speed
If valves are positioned close to the flow cell for fast fluid transitions, then fluid transition speed is improved, but mechanical artifacts and noise increase
Solution Approach 1:
Valves are extracted from the immediate vicinity of the flow cell and positioned at a remote location in the fluid delivery system. This extraction eliminates mechanical vibrations and artifacts generated by valves that would otherwise directly affect the sensitive sensing areas, while the small internal volume of the flow cell maintains fast fluid transition speeds.
3Speed
If valveless junctions with small dead volume are used, then fluid transition speed is improved, but manufacturing precision requirements increase
Solution Approach 1:
The flow cell is designed as a disposable or replaceable component with integrated valveless junctions. The small dead volume features (sharp corners, minimal channel volumes) are incorporated into a low-cost, easily manufactured plastic flow cell that can be replaced rather than precision-machined and reused, reducing the burden of manufacturing precision while maintaining fast fluid transitions.
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 achieves fast fluid transitions and maintains sensitivity and accuracy while reducing costs and maintenance, allowing for efficient biochemical sensing with minimal dilution and mechanical interference, comparable to systems with integrated valves.
Implementation Method 1
fast fluid transitions by minimizing the dead volume between the flow cell and valveless junctions
Implementation Method 2
optical methods based on surface plasmon resonance (SPR) or waveguides... Biochemical molecules show a different refractive index than an aqueous solution. Refractive index changes on the sensor surface result from the addition or subtraction of molecules
Implementation Method 3
Using a resonant element- in case of SPR a metal layer supporting surface plasmons... the local refractive index changes can be then probed using an appropriate illumination and detection scheme
Implementation Method 4
in case of waveguide sensors an optical waveguide supporting optical waveguide modes
Data Source
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AI summary
A flow conduit system (100,200a,200b) suitable for biochemical sensing,the flow conduit system (100,200a,200b) comprising, a first flow cell conduit (1) comprising one or more sensing areas for biochemical sensing; a first selector valve (4); a first inlet/outlet conduit (2) which fluidly connects the first flow cell conduit (1) to the first selector valve(4); a first injection conduit (6) having a first end and a second end; a second injection conduit (7) having a first end and a second end; a fluid injecting means (8) fluidly connected to the second ends of each of the first and second injection conduits (6, 7) so that the fluid injecting means can selectively inject fluids into the first and/or second injection conduits (6,7); wherein the first injection conduit (6) is fluidly connected, at its first end, to the first inlet/outlet conduit (2) by a valveless junction (9), and the second injection conduits (6) is fluidly connected, at its first end, to the first inlet/outlet conduit (2) by a valveless junction (9).