Microfluidic Pressure Regulator for Hydrogel Loading
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Solution Overview
Problem
Current microfluidic systems face challenges in reproducibly loading hydrogels into 3D cell culture models without gel overflow into microfluidic channels, particularly due to pressure fluctuations and burst pressures exceeding the air-cell/extracellular matrix interface, making high-throughput applications cumbersome and unsuitable for certain hydrogels that require rapid mixing.
Innovation Solution
A microfluidic pressure regulator module with capillary burst valves is introduced, which includes a microfluidic channel, microvalves, and reservoirs to divert flowable material into reservoirs upon pressure increase, maintaining the hydraulic pressure within a specified range and preventing gel bursting by adjusting the width of safety microvalves relative to the air-gel interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If microvalves are used to prevent gel bursting, then gel confinement is improved, but operation failure occurs due to internal pressure transients exceeding burst pressure
Solution Approach 1:
The patent introduces a compliance chamber that acts as a pressure buffer before the gel reaches the microvalve. This cushioning chamber absorbs pressure transients and prevents sudden pressure spikes from exceeding the microvalve burst pressure, thereby maintaining both gel confinement and operational reliability
2Manufacturing precision
If syringe pump is used for gel loading, then flow rate control is improved, but system complexity increases and bubble generation occurs during tubing connection
Solution Approach 1:
The patent extracts the pressure regulation function from the external syringe pump system and integrates it directly into the microfluidic device through the compliance chamber and microvalve combination. This eliminates the need for complex external tubing connections while maintaining precise flow control through the embedded pressure regulation mechanism
3Device complexity
If manual micropipettor operation is used for gel loading, then device complexity is reduced, but flow rate consistency deteriorates causing pressure fluctuations and gel bursting
Solution Approach 1:
The patent implements a self-regulating pressure regulation system where the compliance chamber and microvalve automatically adjust to maintain constant pressure during gel loading. The system self-corrects pressure fluctuations without requiring precise manual operation, allowing simple micropipettor operation to achieve consistent flow rates and prevent gel bursting
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 pressure regulator module enables robust, reproducible gel loading under various flow rates without bursting into adjacent channels, allowing for flexible operation in automatic or manual modes and fine-tuning sensitivity and working range, ensuring reliable hydrogel confinement and biotransportation across microtissues.
Implementation Method 1
The microfluidic pressure regulator is based on a simple geometric modification of a capillary burst valve
Data Source
AI summary
A pressure regulator module for a chip-based microfluidic platform is provided. The module includes a microfluidic channel for passing flowable material from the inlet region through the outlet region and into a downstream compartment; one or more microvalves fluidly connected to the microfluidic channel and upstream of the outlet region; and one or more reservoirs fluidly connected to the microvalves, for receiving flowable material diverted by the microvalves, where a flow of flowable material passing from the inlet region toward the downstream compartment is at least partially diverted by the microvalves into the reservoirs as a result of a pressure increase in the microfluidic channel. In some versions, the microvalves are capillary burst valves. A microfluidic chip containing the module and a method of using the module are provided.