Microfluidicists tools

Microfluidic calculator

To help you choose the perfect instrument calibrated for your needs, Elveflow provides a microfluidic calculator. This will help you determine your flow rate, pressure to apply, the best tubing resistance length for your setup, wall shear stress for biology applications, cell culture, and many more.

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This calculator is made of three parts. In Part 1, input fluid properties like viscosity and density. Part 2 is not mandatory, you can use it to calculate the hydraulic resistance inside tubings based on their length, and inner diameter.

Part 3 focuses on your microfluidic chip (PDMS, glass, polymers…) You can describe the channel geometry in a section of the chip, to give its resistance and shear stress. You can use it as a reverse tool if you have a specific shear stress value and want to know the best flow rate to apply.

Part 4 gives results and recommandations to help you chose the perfect flow sensor and pressure controller, advice to improve flow stability with microfluidic resistance length and diameter to target 100 mbar. Test it!

To make the most of our microfluidic calculator, find below a set of dedicated application notes:

Part 1: Fluid properties

Describe the fluid inside your reservoir. Chose predetermined fluid or custom density and viscosity:

Density: Kg/m³
Viscosity: Pa.s

Viscosity η (Pa.s) Density ρ (Kg/m³)

Part 2: Tubing resistance (optional)

Negligible tubing resistance

High tubing resistance

Tubing Inner Diameter (µm) Tubing Length (cm)

Part 3: Channel geometry inside the chip

Describe channel geometry inside your microfluidic chip:

Cylindrical channel*

Diameter d (µm) Length L (mm)

Rectangular channel*

Width w (µm) Height h (µm) Length L (mm)

Part 4: Calculations

Select one information and fill your data to start calculations. Press enter to start and refresh calculations:

Flow rate fixed (µL/min)

Flow rate (µL/min)

Pressure fixed (mBar)

Applied pressure (mBar)

Shear stress at wall τ fixed (dyn/cm²)

Shear stress (dyn/cm²)

Calculator results

Main results:
Flow rate:		µL/min
Pressure:		mBar
Wall shear stress τ:		dyn/cm²
Reynolds number:
Flow state:
Flow velocity:		mm/s

In the channel:
Total volume:		µL
Hydraulic resistance:		Pa.s/m³

In the tubing:
Hydraulic resistance:		Pa.s/m³

Advice:

Low pressure. Add a microfluidic resistance into your setup to increase pressure stability (a section of tubing with thin inner diameter)

Tubing resistance to reach 100 mBar:
Tubing Inner Diameter	Tubing Length
50 µm		cm
65 µm		cm
100 µm		cm
250 µm		cm

Test it in Part 2 tubing resistance

Best flow sensor range suited:
Flow sensor type	Reference	Range
MFS Thermal flow sensor	MFS1	75 nL/min to 1.5 µL/min
MFS Thermal flow sensor	MFS2	420 nL/min to 7 µL/min
MFS Thermal flow sensor	MFS3	2.4 µL/min to 80 µL/min
MFS Thermal flow sensor	MFS4	40 µL/min to 1 mL/min
MFS Thermal flow sensor	MFS5	200 µL/min to 5 mL/min
BFS Coriolis flow sensor	BFS1	1.6 µL/min to 3.3 mL/min
BFS Coriolis flow sensor	BFS2	16.6 µL/min to 33.3 mL/min
BFS Coriolis flow sensor	BFS3	500 µL/min to 500 mL/min

Best pressure-based flow controller range:
Flow controller	Pressure range
OB1 MK3+ pressure controller	-900 to 1000 mBar
OB1 MK3+ pressure controller	0 to 200 mBar
OB1 MK3+ pressure controller	0 to 2000 mBar
OB1 MK3+ pressure controller	0 to 8000 mBar

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Calculator made by Kalyan VEERENDRA, Julien RIDOUARD, Jessica AYACHE, Lisa MUIZNIEKS and Marie GEMEY. Contact Elveflow team at contact@elveflow.com