How to perform an ultrafast microfluidic medium switch with an Elveflow® pressure & flow control instrument (OB1)

SET-UP TIME : 15-20 MIN / DIFFICULTY : *****


This application note shows how to perform an ultrafast microfluidic medium (drugs, samples, etc) change in an hypothetic chemical or biological environment, performed with an Elveflow® pressure & flow control instrument (OB1) as shown in these pictures:

Microfluidic fast medium switch (Elveflow OB1)

* We propose another configuration (using an Elveflow OB1 and am Elveflow MUX standard) to perform a microfluidic fast flow switch. Click here to see the Application Note.

We also recommend to see the following review comparing the two configurations (OB1 or OB1+MUX).

For fast medium switch in perfusion chambers or one inlet microfluidic chips, discover our dedicated Perfusion Pack.

List of components 

You can find each of these elements in the following gallery:

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Setup Diagram

This picture shows the microfluidic setup that will be used in this application note.

Microfluidic fast medium switch (OB1) Full setup

As often as possible avoid using soft tubing (like Tygon) which involves compliance and then increases the response time of the system.
If you’re not familiar with microfluidic tubings, you may read our dedicated tutorials.

The following diagram illustrates the complete chain of elements involved in this application note. You will need to assemble all these parts to set up your experiment:

Microfluidic fast medium switch (OB1) Diagram


Using the Elveflow® smart interface to perform an ultrafast medium switch:

Make sure that all the cables and tubing are well connected to your Elveflow device (USB cable, 24V DC, etc).

Perform leakage tests and remove any air bubbles before starting your experiment to ensure a good flow regulation.
Knowing what fitting is best suited for your needs is a first step towards success. If you’re not familiar with microfluidic fittings, you may read our specific tutorials.

In order to monitor the pressure to perform an ultrafast medium switch, it is necessary to follow the next steps:

  • Step 1 - Open the Elveflow® smart interface on the computer and select the OB1. (“OB1Mix01” in the example case)
  • Step 2 - Back on the main window, set an initial desired pressure rate value in mbar for each one of the three different mediums (100 mbar in the example case) on the pertinent channels (channels 1, 2 and 3 in the example case). Press the “Apply” button.
  • Step 3 – Increase or decrease the pressure rate on the different channels until finding the equilibrium on the three mediums (the three mediums will converge and pass through the main channel without mixing with a laminar flow) (See the picture). These equilibrium pressure rates will ideally not be far from being the same or very similar on the three channels but it will depend on different factors, such as the different density of the mediums used, the different resistivity of the setup (the number and type of connectors, the length of the tubing used, etc).
  • Step 4 – Once the equilibrium pressure rates have been set, decrease the pressure of the two mediums you want to stop until they stop flowing through the main channel. Then add this pressure configuration as a step of a microfluidic project with the desired length (4 seconds on the example case).
  • Step 5 – Repeat Step 4 for the other mediums.
  • Step 6 – Press the “Play” button to start performing the project.

Set the desired maximum and minimum shown parameters on the display window for pressure and flow rate and press the play icon to launch the pressure and flow rate profiles display.

Select the channels you want to display by ticking the corresponding boxes on the channel display selection block.

The screenshots corresponding to these steps are in the following gallery:

Congratulations! You’ve achieved an ultrafast medium switch using an Elveflow® OB1!


We  provide the only microfluidic flow control system using Piezo technology that enables a blazing fast flow change in your microdevice.

Piezo electric microfluidics flow control