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

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

Abstract

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

* We propose another configuration (using an Elveflow OB1 and am Elveflow MUX standard) to perform a microfluidic fast medium 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 microfluidic medium switch in perfusion chambers or one inlet microfluidic chips, discover our dedicated Perfusion Pack.

Setup Diagram

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

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:

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Protocol

Using the Elveflow® smart interface to perform a fast microfluidic 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 a fast 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 relevant 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.

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