Diffusion-Bonded Sample Channels for Low-Carryover Liquid Chromatography
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Solution Overview
Problem
Liquid chromatography systems face issues with carryover, poor peak shape, and increased chances of leakage and contamination due to the large number of tubing connections required to establish fluidic path configurations, which also lead to variations in tube volumes affecting chromatographic results.
Innovation Solution
A multi-channel fluidic device with a diffusion-bonded body having internal microfluidic channels, where stator surfaces are used to internally couple fluid ports between rotary valves, reducing the need for external tubing and minimizing unswept volumes, thereby enhancing precision and reducing installation time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple valves are coupled with tubes to achieve desired fluidic path configuration, then fluidic connectivity is established, but the number of connections increases leakage risk and contamination chances
Solution Approach 1:
The patent merges multiple separate valve components and their connecting tubes into a single integrated diffusion-bonded body. The fluidic channels are built internally within the bonded structure, eliminating the need for external tube connections between valves. This combining approach directly reduces the number of connections while improving reliability.
Solution Approach 2:
The patent embeds fluidic channels inside the diffusion-bonded body structure itself. The channels are nested within the walls and interfaces of the bonded layers, allowing fluid flow paths to be contained within the device structure rather than requiring external tubing.
2Measurement precision
If multiple tube connections are used to establish fluidic paths, then fluidic connectivity is achieved, but unswept volumes cause carryover and poor peak shape
Solution Approach 1:
The patent extracts and eliminates the external tube connections and their associated unswept volumes from the system. By moving the fluidic paths inside the diffusion-bonded body, the design removes the problematic external tubing that creates carryover issues.
Solution Approach 2:
The fluidic channels are nested within the diffusion-bonded body structure, ensuring that all channel volumes are swept and controlled. The internal channel design eliminates dead volumes at connections, as the channels are continuously defined within the bonded material.
3Productivity
If manual tubing installation is performed, then fluidic connections are established, but significant installation time is required
Solution Approach 1:
The patent combines multiple valve bodies and their internal channels into a single pre-assembled diffusion-bonded unit. This integration means the device arrives ready-to-use with all fluidic paths already established, eliminating the time-consuming manual tubing installation process.
Solution Approach 2:
The fluidic channel configuration is performed in advance during the diffusion bonding manufacturing process. All channel connections and routing are established before the device reaches the user, so no manual installation or configuration is needed at the point of use.
4Measurement precision
If tube inner diameter manufacturing tolerances vary, then tube volume differs, but chromatographic results become inconsistent
Solution Approach 1:
The patent replaces multiple separate tubes with a single integrated diffusion-bonded structure. The channel dimensions are defined by the bonding process itself rather than by assembling multiple tubes with varying tolerances, leading to more consistent and precise volume control.
Solution Approach 2:
The patent changes the manufacturing approach from mechanical tube assembly to diffusion bonding. This process change allows for tighter dimensional control and more precise channel volume definition, eliminating the variability introduced by tube inner diameter tolerances.
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 solution reduces leakage and contamination risks, improves chromatographic band dispersion, and achieves precise volume control for sample channels, allowing for more accurate and reliable chromatographic measurements.
Implementation Method 1
a diffusion-bonded body having internal microfluidic channels
Data Source
AI summary
Described is a multi-channel fluidic device that includes a diffusion-bonded body having a device surface and a plurality of fluid channels. Each fluid channel includes a channel segment defined in a plane that is parallel to the device surface and parallel to each of the planes of the other channel segments. The plane of each channel segment is at a depth below the device surface that is different from the depth below the device surface for the other planes. Each channel segment may have a volume equal to the volume of each of the other channel segments. One of the fluid channels may include a plurality of channel segments serially connected to each other and each defined in a plane that is different from the planes of the other channel segments.