Microfluidic Check Valve for Chromatography Backflow Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid chromatography systems, back flow and pressure pulses occur when switching from bypass to main-pass mode, causing disturbances in the stationary phase, sample dispersion, and reducing data quality, which existing solutions like pre-pressurization or injection valve modifications do not fully address without additional complexities.
Innovation Solution
A microfluidic check valve with a body, inlet and outlet bores, and a freely movable disk that responds to pressure differentials to allow forward fluid flow while preventing back flow, capable of withstanding high pressures and maintaining a nanoliter-scale volume, is integrated into the fluid flow path to prevent pressure pulses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the injection valve is switched from bypass mode to main-pass mode, then the sample can be delivered to the column, but back flow and pressure pulses occur causing disturbances in the stationary phase and sample dispersion
Solution Approach 1:
A check valve is introduced as an intermediary component in the fluid path between the injection valve and the column. This check valve allows forward flow when pressure is applied from the pump but prevents back flow when pressure reverses during valve switching, thereby eliminating pressure pulses and stationary phase disturbances while maintaining sample delivery capability
2Reliability
If pre-pressurization of the sample loop is implemented, then back flow can be reduced, but the system complexity and operational complexity increase
Solution Approach 1:
The check valve is designed to automatically respond to pressure differentials without external control. It opens when forward pressure is applied and closes when back pressure occurs, providing self-regulating back flow prevention without requiring pre-pressurization sequences, additional valves, or complex control logic
3Reliability
If the disk is made freely movable to respond to pressure differentials, then the valve can prevent back flow, but the valve must withstand high pressures up to 1200 bar
Solution Approach 1:
The traditional mechanical check valve design using springs and moving parts is replaced with a microfabricated disk structure that relies on pressure differential forces alone. The disk is anchored at its periphery and freely movable at its center, allowing it to respond to pressure differentials without mechanical actuators, while the microfabricated structure and material selection enable it to withstand pressures up to 1200 bar
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 microfluidic check valve effectively prevents back flow and pressure pulses, ensuring stable fluid flow and reducing sample dispersion, even at high pressures, thereby enhancing the performance and longevity of chromatography columns.
Implementation Method 1
The disk is freely movable between an open position and a closed position in response to a pressure differential between the inlet bore and the outlet bore
Data Source
AI summary
A microfluidic check valve includes an inlet bore, an internal chamber, an outlet bore, and a disk freely movable in the chamber between an open position and a closed position. At the open position, the disk permits fluid to flow from the inlet bore, through the chamber, and to the outlet bore. At the closed position, the disk prevents fluid from flowing in the reverse direction from the chamber into the inlet bore. The check valve may be positioned in-line with a fluid conduit, and/or incorporated with various fluidic devices such as, for example, capillary tubes, fittings, and chromatography columns. The check valve is capable of withstanding high fluid pressures, while featuring a small swept volume, such as a nano-scale volume. The check valve may be utilized, for example, to prevent fluid back flow and isolate pressure pulses in fluid flow systems.