Gas-Liquid Reservoir Control for Flow and Dissolved Gas Decoupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current systems for controlling oxygen concentration in cell cultures, such as those used in microfluidic and organ-on-chips technologies, face challenges in independently managing the flow rate and dissolved gas concentration of liquid media, leading to inefficiencies and long response times.
Innovation Solution
A device comprising a liquid reservoir with a gas inlet and outlet, connected to admission and emission lines with control valves, allows for independent control of gas concentration and flow rate through sensors and pressure management, enabling rapid adjustment of dissolved gas levels and flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If pressure-based controllers are used to control liquid flow rate, then flow rate can be controlled, but dissolved gas concentration cannot be controlled independently
Solution Approach 1:
The system is divided into separate control modules: a pressure control module for regulating liquid flow rate and a gas composition control module for managing dissolved gas concentration. This segmentation allows independent control of each parameter without interference between them.
Solution Approach 2:
An intermediary gas phase is introduced between the liquid reservoir and the microfluidic system. By controlling the gas phase composition and pressure, the system can independently regulate both liquid flow rate (through pressure) and dissolved gas concentration (through gas-liquid equilibrium), decoupling these two control functions.
2Stress or pressure
If standard pressure controllers with two valving systems are used, then pressure can be controlled, but response time when changing gas composition is long
Solution Approach 1:
The emission valve function is extracted and applied specifically to the gas phase rather than controlling both gas and liquid flow. This allows the admission valve to focus on rapid gas composition changes while the emission valve independently manages gas removal, significantly reducing response time for gas composition adjustments.
Solution Approach 2:
The system uses dynamic control of gas flow rates through independently adjustable valves, allowing rapid adaptation of gas composition in the headspace. This dynamic control enables quick response to changing experimental requirements without the delays inherent in traditional dual-valving pressure controllers.
3Speed
If syringe pumps are used to generate medium flow, then flow rate can be controlled, but dissolved gas concentration in the syringe cannot be controlled once filled
Solution Approach 1:
The desired gas composition is established in the headspace of the liquid reservoir before liquid flow begins. This preliminary action ensures that the liquid becomes saturated with the required dissolved gas concentration as it passes through the gas phase, eliminating the need for post-filling gas control in closed syringe systems.
Solution Approach 2:
The system uses gas phase pressure and composition control to regulate both liquid flow rate and dissolved gas concentration. By applying pneumatic principles to the gas headspace, the system achieves dual control functionality that mechanical syringe pumps cannot provide once filled.
4Speed
If peristaltic pumps are used to generate medium flow, then flow can be generated, but pulsations are induced making them poorly adapted to many applications
Solution Approach 1:
The mechanical peristaltic pumping action is replaced with a pressure-based flow control system. Gas pressure applied to the liquid reservoir provides smooth, pulsation-free liquid flow through the microfluidic channels, eliminating the rhythmic mechanical disturbances characteristic of peristaltic pumps.
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 solution enables precise and efficient control of dissolved gas concentrations and flow rates in cell cultures, improving the simulation of in vivo conditions and reducing the complexity and cost of cell culture systems.
Implementation Method 1
a gas inlet (7) configured for introducing a gaseous medium into the liquid medium contained in said liquid reservoir (4)
Implementation Method 2
the admission line (5) comprises at least one control valve (12) and the emission line (6) comprises at least one control valve (15)
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The present invention relates to a device (2) for providing a liquid medium with a controlled flow rate and with a controlled concentration of a dissolved gas, the device (2) comprising: - a liquid reservoir (4) provided with: - at least one gas inlet (7); - at least one gas outlet (8); and - at least one liquid outlet (9); - an admission line (5) configured to provide a gaseous medium into the liquid reservoir (4), the admission line (5) being connected to the at least one gas inlet (7) and comprising at least one control valve (12); and an emission line (6) configured to withdraw the gaseous medium from the liquid reservoir (4), the emission line (6) being connected to the at least one gas outlet (8) and comprising at least one control valve (15). The present invention further relates to an assembly comprising said device, and to a method for providing a liquid medium with a controlled flow rate and with a controlled concentration in a dissolved gas.