Microfluidic Sample Handling via Electrokinetic Flow Path
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Solution Overview
Problem
Existing microfluidic systems face inefficiencies in handling multiple samples due to uncontrollable current flows caused by voltage drops across highly resistive depletion regions, leading to potential chip failure and reduced throughput.
Innovation Solution
The system introduces a flow path that moves a second sample from its well to a first sample well instead of a side channel, allowing for efficient redirection to the injection point with minimal delay, using electrokinetic forces and controlled voltages/currents to manage sample movement and avoid depletion region issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If samples are moved through side channels to auxiliary wells, then sample handling is possible, but highly resistive depletion regions form causing uncontrollable current flows and potential chip failure
Solution Approach 1:
The invention extracts the harmful depletion region formation by removing samples from the main electrolyte channel and directing them through separate sample wells with independent electrolyte reservoirs. This separation prevents the formation of highly resistive depletion regions in the main channel while still enabling sample transport and processing.
Solution Approach 2:
The invention introduces sample wells as intermediary structures between the sample injection point and the detection channel. These sample wells serve as buffer zones where samples can be held and prepared without interfering with the main electrolyte flow, thus preventing depletion region formation while maintaining sample handling capability.
2Productivity
If samples are moved sequentially through the injection channel, then sample analysis is possible, but time delays between sample injections reduce throughput
Solution Approach 1:
The invention performs preliminary actions by pre-positioning multiple samples in separate sample wells before the analysis begins. This allows the system to quickly switch between samples by simply changing which well is connected to the injection channel, eliminating the need for time-consuming sequential transport and reducing injection delays.
Solution Approach 2:
The invention implements dynamic switching between different sample wells connected to the injection channel. By making the sample well connections reconfigurable, the system can dynamically select which sample to inject next, enabling rapid sample turnover and increasing overall throughput without compromising analysis quality.
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 increases the throughput of the microfluidic system by reducing the growth of depletion regions, preventing uncontrollable current flows, and extending the system's lifespan by allowing for efficient handling and separation of multiple samples with reduced time delays and voltage drops.
Implementation Method 1
The injection of the sample plug into the electrolyte channel is accomplished electrokinetically by applying an electric field across the supply and drain channels
Data Source
AI summary
A method for handling samples in a microfluidic system is described. The microfluidic system includes an injection channel fluidically coupled to an injection point adapted for injecting an amount of fluid, a first sample well containing a first sample, the first sample well being fluidically coupled with the injection channel, and a second sample well containing a second sample, the second sample well being fluidically coupled with the injection channel. The method includes moving the second sample from the second sample well towards the first sample well.