Pressure-Driven Injection for Microfluidic Separations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional microfluidic methods for electrospray ionization and sample processing in mass spectrometry face challenges with injection bias and ionization suppression due to electrokinetic flow, which limits the effectiveness of sample focusing and separation efficiency.
Innovation Solution
The implementation of pressure-driven injection methods in microfluidic devices, allowing for precise control of sample volume and elimination of electrokinetic injection bias by using defined pressures in the background electrolyte and sample reservoirs, enabling efficient sample delivery and electrophoretic separation without the need for voltage differentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If electrokinetic flow is used for sample injection, then sample can be delivered into the separation channel, but injection bias occurs and ionization suppression is caused
Solution Approach 1:
The patent replaces the electrokinetic injection mechanism (electrical field-driven) with a pressure-driven mechanical injection system. By applying controlled pressure to the sample reservoir, samples are injected into the separation channel without the electrokinetic effects that cause injection bias and ionization suppression, thereby improving injection accuracy while maintaining ease of operation.
2Productivity
If voltage differentials are applied for sample injection, then sample delivery is achieved, but electrokinetic injection bias is introduced
Solution Approach 1:
The patent substitutes voltage differential-driven electrokinetic injection with pressure-driven mechanical injection. Controlled pressure applied to the sample reservoir enables efficient sample delivery into the separation channel while eliminating the electrokinetic injection bias that degrades measurement precision, thus achieving both high productivity and injection precision.
3Ease of operation
If conventional microfluidic methods are used, then sample processing is achieved, but separation efficiency is limited
Solution Approach 1:
The patent replaces conventional electrokinetic sample processing methods with pressure-driven injection followed by electrophoretic separation. The pressure-driven injection provides precise sample delivery without injection bias, and the subsequent electrophoretic separation in the microfluidic channel achieves high separation efficiency, thereby improving productivity while maintaining ease of operation.
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 reduces injection bias, enhances separation efficiency, and allows for online sample concentration methods like transient isotachophoresis, improving the analysis of samples with varying electrical conductivity and viscosity, thereby improving the overall performance of microfluidic sample processing systems.
Implementation Method 1
concurrently applying a defined pressure to the background electrolyte reservoir and a defined pressure to the sample reservoir
Implementation Method 2
electrophoretically separating the delivered sample in the separation channel by applying a voltage to the background electrolyte reservoir and a downstream location of the separation channel
Implementation Method 3
electrospray ionization involves the use of electric fields to disperse a sample solution into charged droplets
Data Source
AI summary
Methods, systems and devices that allow independently applied pressures to a BGE reservoir and a sample reservoir for pressure-driven injection that can inject a discrete sample plug into a separation channel that does not require voltage applied to the sample reservoir and can allow for in-channel focusing methods to be used. The methods, systems and devices are particularly suitable for use with a mass spectrometer.