Application Note

Gas flow control for benchtop bioreactors

with flexible gas flow controller

Bronkhorst offers gas flow control for bioreactor manufacturers and has a gas flow controller available especially for use in benchtop bioreactors. This flexible instrument has a wide dynamic range allowing the bioreactor manufacturer for easy change of flow range and switching to other gas types with one instrument. This way you can benefit from model reduction, allowing you for local stock and therefore, independency of lead times.

Most bioreactors, whether they are used for fermented food and drinks or development of vaccines and medicines, need to be supplied with gases for growing bacteria, yeast or cells for the desired biological synthesis to take place. These gases are usually added continuously over a period of a few days to several weeks using flow controllers.

Check out the Bronkhorst solution
Flow control in benchtop bioreactor

Requirements for benchtop bioreactors

For a reliable biological growth process, accurate, repeatable, and stable gas flows are essential. Especially in the R&D environment, a wide range of gas flow rates is necessary to investigate the best growth conditions. For benchtop bioreactors compact gas flow instruments are desired. For manufacturers that build bioreactors on specification for customers, it is desirable to reduce the number of variations of flow instruments, to counteract obstacles in delivery time. Moreover, pressure data is desired to inform the bioreactor user about the current process conditions.

Check our recommended products

Important topics

  • Large dynamic flow range
  • Easy switching of gas type
  • High accuracy, repeatability and long-term stability
  • Pressure information
  • Compact

Process solution

Large dynamic range

Bioreactor manufacturers would like to build reactors that are as generic as possible, to provide a system for a variety of users. Ideally, one bioreactor setup handles a wide range of gas flow rates. For this application, the FLEXI-FLOW mass flow controller is equipped with an unique flow sensor that measures and controls flow over a wide dynamic range (a high turndown ratio of 1:1000) in combination with excellent accuracy and compatibility with different gas types.

Flow scheme

Easy switching of gas type

As air, oxygen, nitrogen and carbon dioxide are the most common gases in this field, the FLEXI-FLOW has the data of these gases standard on board, so there is no need for additional calibration. Using the on-board Fluidat firmware, you can easily calculate the physical properties of gases, allowing you to reduce the number of instruments needed.

Where a typical range up to 20 ln/min with four gases has been traditionally covered by 36 models, this can be reduced to 12 models, and with four gases on board even to 3 mass flow controller models. The bioreactor manufacturer and the end-user can decide which of these gases to use by setting a parameter in the software.

FLEXI-FLOW flow controller enabling model reduction
Reduction of gas flow controllers possible

Long-term stability

Due to a capillary chip sensor technology combined with friction-free valve technology and electronics, the FLEXI-FLOW instrument has an excellent accuracy, repeatability and long-term stability. The capillary chip sensor that measures the gas flow remains very stable over the years and does not need calibration. Since the small sensor is less prone to temperature gradients, the short-term stability is very good as well.

Pressure information

Pressure information is desired to inform or alarm the bioreactor user. This accounts for gas supply pressure at the inlet and bioreactor process pressure at the outlet. Limitation of the process pressure is necessary for bioreactors to avoid breakage of the reactor. The FLEXI-FLOW gas flow controller contains pressure measurement and control at the inlet and outlet of the instrument, and as such, this smart instrument is suitable for predictive maintenance of the bioreactor system.


The small size of the FLEXI-FLOW instrument will make it a device of choice for compact benchtop bioreactors.

Ask advice

Do you need advice on gas flow meters for benchtop bioreactors? Contact us

Please select the type of question you have
Do you have problems filling out this form? Please contact us by email ([email protected]).