The NIFS: a non-invasive flow sensor for sterile microfluidic setups
Fluigent has over 15 years of experience in pressure-based liquid handling solutions. Our products are designed by microfluidic experts to produce stable and precise flow rates that meet a variety of application needs.
Today, several microfluidic applications - from drug screening to organ-on-a-chip studies - require a contamination-free environment as well as stable and precise flow rates. In this regard, flow sensors are used to monitor flow rates, implying direct contact with liquids and causing potential complications. Not only do the flow sensors require calibration, they are also subject to clogging issues and do not ensure a sterile setup.
To address these matters, Fluigent has developed new and disruptive technology: the NIFS, allowing for contactless live flow rate monitoring and regulation. Using Fluigent’s self-learning algorithm, the NIFS can deduct fluid flow rate from gas flow rate measured at the outlet of a pressure controller.
In today’s newsletter, you’ll discover the NIFS and how it can be implemented in a setup using one of our high-precision pressure controllers: the F-OEM.
Description of the setup & components used
The NIFS, our new OEM non-invasive flow sensor, precisely monitors all desired flow rates in a range of 100µL/min to 10mL/min without being in contact with liquid (no calibration needed).
The F-OEM, one of our OEM pressure controllers which controls pressure with accuracy and stability, displays pressure ranges from -800 mbars to 7 bars.
The F-OEM pressure controller (1) is composed of an electronic board coupled with a pressure module. A pressure supply is connected to the F-OEM pressure module. The NIFS (2) is pneumatically connected between the pressure manifold and its dedicated reservoir (3). The pressure pushes the liquid through the liquid tubing, which subsequently flows into the microfluidic chip (4) dedicated to cell culture under perfusion. Flow rate and pressure are monitored through our software OxyGEN (or SDK for full system integration) on a computer (5).
NIFS’ performance
Here, the NIFS performed flow rate steps from 100µL/min to 600µL/min. It takes approximately 30 seconds to reach the first 100µL/min, during which the algorithm learns from the system to adjust to the desired flow rate. With this information, the next steps are accurately reached in a limited amount of time (<10 seconds).
Flow rate stability
The stability of the flow rate at 200µL/min was evaluated for 10 minutes using the NIFS. We can see that our non-invasive flow sensor allows for unique stability (<5% accuracy) during the duration of the test, combined with highly stable pressure values. This makes it usable for a wide range of applications necessitating stable flow rates, including cell cytometry or cell perfusion.
The NIFS, coupled with one of our high-precision pressure controllers, provides users with the ability to perform microfluidic experiments requiring controlled flow rates in a 100% contamination-free environment. As shown above, the NIFS allows for the production of highly stable and precise flow rate control with high accuracy (<5%) over a wide range of flow rates (from 100µL/min to 10mL/min), making it suited for all types of microfluidic applications.