In order to conduct experiments in microfluidics effectively, it is necessary to master various microfluidic technologies to use the most appropriate method to control microfluidics. Some microfluidic technologies have been developed. This article aims to briefly introduce the main microfluidic technologies and their advantages and disadvantages.
Pressure Control
Pressure is a good tool for controlling microfluidic flow. There are many ways to use pressure: hydrostatic or pressure regulator.
- Using hydrostatic pressure is the easiest way to move fluid-place the inlet reservoir above the outlet reservoir so that gravity moves the fluid from the inlet to the outlet.
- The pressure pump works by pressurizing the sample container to control the pressure drop between the inlet and the outlet of the microfluidic system. The responsiveness of the generated flow depends on the responsiveness of the pressure pump.
Advantages of pressure pumps in microfluidics:
- Pulseless flow control
- Excellent stability
- Can control the flow in the dead-end channel
- Both pressure and flow rate can be controlled in one device
- The ability to determine the exact pressure inside the microfluidic component
Disadvantages of pressure pumps in microfluidics:
- Limited to 8 bars
- Flow switches with multiple entry points may cause backflow
Volume Control
Using volume control is another way to control microfluidic flow.
The syringe pump is the most commonly used flow control system in microfluidics. However, the flow rate of the syringe pump is not constant. This discontinuity is caused by the mechanical system that generates the oscillating flow. For certain experiments, such as biological experiments, this may be problematic.
Advantages of syringe pumps in microfluidics:
- Upper pressure limit
- No change in syringe speed
Disadvantages of syringe pumps in microfluidics:
- Pulsating flow
- Unable to control the flow in the dead-end channel
- Difficult to determine the exact pressure inside the microfluidic component
Peristaltic pumps are another mechanical system used for microfluidic control. Like other technologies, peristaltic pumps have their advantages and disadvantages.
Advantages of peristaltic pumps in microfluidics:
- Easy to set up
- A large number of samples can be injected
Disadvantages of syringe pumps in microfluidics:
- Low experiment reproducibility
- The flow rate is not constant due to the stretching of the pipe
Other Technologies
Electroosmotic pumps or integrated micropumps are also a method of controlling the flow of microfluidics, which are more specific.
- The main idea of an electroosmotic pump is to generate electroosmotic flow in porous media. It works due to the external power applied to the electric double layer, and this action generates high pressure and high flow rate.
- The integrated micropump is the latest flow control technology. Mainly based on the principle of peristalsis, a flexible membrane made of PDMS.
Tips for Improving Microfluidic Settings
- Avoid creating bubbles in microfluidic devices: There are a variety of accessories available in the microfluidic market, such as our bubble trap kit.
- Hands-free operation: Tools can be used to start/stop the flow of the microfluidic device or switch its configuration with your feet.
- Automated settings: Some software tools can monitor each compatible component of the settings to automate the settings.
- Unique software: Designed to simplify your operation and allow you to monitor microfluidic devices in real-time.