A Microfluidic Pressure Controller Comparison for Your Ultimate Fluid Control System

In this comprehensive fluid control system comparison article, we rigorously test and discuss the differences between 3 categories of pressure controllers:?

• Cost-effective?
• Mid-range?
• Premium pressure controllers?

We emphasize evaluating product performance and examining their seamless integration into microfluidic systems, considering factors such as user-friendliness and integration capabilities.??

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Full webpage here: https://www.fluigent.com/microfluidic-oem/technologies/pressure-controller-comparison/?

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How to choose the right microfluidic flow control system?

Microfluidic technology is widely used in academic research for a myriad of applications in life sciences, chemistry, and food. It is also becoming increasingly popular in analytical device and bioreactor industries, as it brings a new level of analysis and offers several benefits, including more reliable results while minimizing reagent consumption.??

Popular scaled applications today include microfluidics for cell biology, fine perfusion, and organ on a chip studies, or droplet microfluidics for biological encapsulation (digital PCR, organoids).?

In the crowded jungle of pressure controllers and regulators, what is the best pressure controller for microfluidics??

What are the different pressure controllers??

We identified 3 different types of pressure controllers available in the market for users to choose from. We compared them in terms of cost-effectiveness and quality.?

• Cost-effective pressure controllers are the most basic and affordable option. They typically have lower performance compared to the medium and premium options.??
• Medium pressure controllers offer a balance between affordability and performance. They provide improved performance compared to cost-effective pressure controllers, but still find??
• Premium pressure controllers, as the name suggests, offer the highest level of accuracy and stability. They are designed for applications where precision and reliability are of utmost importance, which is usually the case in microfluidics. Here the pressure controllers used are the Fluigent Flow EZ and F-OEM??

Firstly, we compare the 3 pressure controllers in terms of performance (accuracy, stability, response time), and next focus on usability and integration capabilities. We finally discussed the achievable applications for each device.??

Choosing a pressure controller based on performance?

When choosing a pressure controller, a common practice is comparing specifications listed on product technical documentation such as product datasheet or user manual. There are several important parameters to consider such as product accuracy, repeatability, or response time.??

Although a good approach to eliminate products that are beyond doubt out of specifications, it is a complex exercise as some manufacturers give specifications based on the sensor or valve that compose the pressure controller, while others tend to provide data based on real tests.??

In addition to specifications, what makes the general performance of a pressure controller is its regulation algorithm. In fact, basic pressure controllers only provide analog communication based on voltage, while some can provide PID controllers that allow giving live feedback loops and adjusting the pressure based on the pressure sensor feedback. It ultimately affects pressure stability, accuracy, response time, and pressure transitions.??

How accurate and stable is your pressure controller?

Accuracy is a crucial factor to consider when choosing a pressure controller. A pressure controller with high accuracy ensures that the desired pressure setpoint is achieved. In addition, pressure stability is a crucial factor to consider when choosing a pressure controller, as many applications rely on stable pressurization processes.?

?Figure 1 shows pressure accuracy and stability for the cost-effective, medium, and premium pressure controllers. Looking at the average, it is possible to see that both cost-effective and medium-pressure controllers show a shift in accuracy compared to the targeted value of 750 mbar with a difference of more than 2 mbar. This is likely linked to the fact that both products do not have live calibration capabilities, inducing a shift compared to the targeted value, ultimately generating noise (see figure 2).?

Figure 2: Inherent noise of a medium pressure controller without available calibration??

Enhanced stability and accuracy over the long term with the premium system?

Using the premium pressure controller, the average value is 749.81 mbar, +/- 0.082 mbar. The premium pressure controller is the most accurate device with less than 0.2 mbar shift compared to the targeted value, making it the most performant product in terms of accuracy.?

Another parameter we can analyze here is stability. We observe that with the cost-effective system, 750 mbar is achieved at the start of the experiment but in less than an hour we can observe a shift in the applied pressure, transitioning from 749 mbar after ~30 min and 748 mbar after a few hours. We observe similar pressure drift with the medium pressure controller, with a lower degree of magnitude (747.5 to 747 mbar).??

Utilizing the premium pressure controller, the pressure of approximately 749.8 mbar remains stable for over 8 hours without exhibiting any drifts. Additionally, we observe enhanced stability and accuracy over the long term, as it is consistently maintained within the required pressure range with commendable stability.?

Response time: how fast do you want to change pressure??

Response time is another important factor to consider when choosing a pressure controller. A pressure controller with good performance will be able to quickly respond to changes in pressure and maintain stability.??

The response time of a pressure controller is a critical factor in microfluidics due to the precise and often delicate nature of processes within these systems. A pressure controller with a quick and accurate response time ensures that when setpoints or external conditions change, the system can adapt rapidly and maintain the desired pressure with minimal overshot or oscillations. This is essential for maintaining the integrity of experiments or processes, as delays or inaccuracies in pressure adjustment can result in compromised data, ineffective fluid control, and potentially damage sensitive microfluidic components.?

A Better response time with the premium fluid controller?

Figure 3 shows pressurization and depressurization using the medium pressure controller and premium controller. When using the medium pressure controller, for pressurization we observe the time to reach 98% of the targeted value is 0.8 seconds while using the premium pressure controller 0.8 seconds. For depressurization we observe the time to reach 98% of the targeted value is 0.7 seconds while using the premium pressure controller 0.1 seconds.?

This shows the medium pressure controller and premium pressure controller have similar response time for pressurization for a transition at 100 mbar, while depressurization is about 10 times faster with the premium pressure controller.?

Additionally, when one needs to stop a fluidic protocol, depressurization time will depend on the pressure controller used. Graph 4. shows the depressurization time from 500 mbar to 400 mbar using the medium and premium pressure controllers. We can observe it takes 0.7 s and 0.1 s using the medium and premium pressure controllers respectively.??

Depressurization time has a great impact on microfluidic protocols, as during the depressurization time liquids are still injected even though the experiment has ended. Precious liquids injected during the depressurization time are wasted, which ultimately has an impact on experiment costs. Depending on the system used and the related fluidic resistance, depressurization time can take more than tenths of seconds!?

The smoother the better: Product algorithm and PID ultimately affect performance?

As mentioned in the above paragraphs, product specifications do not make it all. PID and algorithms also have an impact on performance. Figure 5 shows the pressure curvature during a transition from a higher pressure for the medium pressure controller. We can observe some jabbering when transitioning to 100 mbar, which is not observed using the premium pressure controller (figure 5).?

In our comparative analysis between pressure controllers, we observed noticeable differences in performance, particularly in terms of accuracy and stability. Both cost-effective pressure controllers exhibited more pronounced fluctuations and required a longer duration to achieve a state of equilibrium. Additionally, it stabilized within a less precise pressure range compared to its counterpart.?

On the other hand, the premium product demonstrated a remarkably smoother and more stable transition profile. It efficiently and rapidly attained stability, aligning closely with the desired precision levels.??

This superior performance in maintaining consistent pressure control under varying conditions underscores the premium product’s advanced engineering and design.??

Such characteristics are particularly vital in microfluidics applications where exact pressure control is crucial for the integrity and accuracy of the results.?

Read our full webpage here: https://www.fluigent.com/microfluidic-oem/technologies/pressure-controller-comparison/?