Millifluidic system, how could i make it?

I’m not sure I really understand the Millifluidic system properly.

As far as I understand, Millifluidic systems require a total of four components.

The first is Millifluidic Devices.

Thankfully, fabrication details and detailed processing methods are shown in the publication.

We are a pure bio lab without any mechanical equipment like a laser cutter, so it would be impossible to make it ourselves, but it seems that we can entrust it to the related companies.

The problem is the design of it. Original publication designed it the branch to extend from one input, but the Liu’s ePACE system designed it to connect only one input to single output.

Of course, there is an advantage of original one that individual output can be controlled by on/off, and Liu’s must control all outputs at once.

However, this is simply the difference in the number of connected solenoids and Pneumatic Valves, not the difference resulting from design.

I’m curious about your opinion as to which of these two is a better design method.

The second is solenoid bank.

This is simple switch that open and close the air-fluidic line entering Millifluidic Devices.

It is also considered the simplest part of the Millifluidic system because it is sold as commercial product.

Of course, in order to control individual solenoids, a process of connecting and programming with Arduino is needed, but I think this part will work out somehow.

The third is the pressure regulator.

The pressure regulator controls the pressure flowing constantly into the solenoid.

Since Pneumatic Valves are very sensitive to pressure, it is very important to maintain a constant pressure.

The question here is, does the vacuum also need to be adjusted with a pressure regulator?

There is no reference to the vacuum source, so I wonder if it needs to be adjusted separately or if I can connect it directly to any vacuum source to solenoid without any adjustment.

In addition, a standardized SA eVOLVER boards was used in Liu’s pressure regulator.

I wonder if standardized SA eVOLVER boards must be used in the pressure regulator.

Or is it simply used for integrated control by Raspberry Pie, or is integrated control impossible without SAeVOLVER boards?

This is the most difficult and challenging part for me, because it is fully self-made.

No reference design, no buleprint, no code, so if you have any tips and know-how on the pressure regulator, i would appreciate it if you could share it with me.

The last thing is pressure source and vacuum source.

The solenoid bank and pressure regulator are simply devices that control pressure and vacuum entering Millifluidic Devices.

Opening and closing the Pneumatic Valves of Millifluidic Devices is fully depending on pressure and vacuum, so the source is needed to provide it.

I wonder how you have a pressure source and a vacuum source.

I may use the vacuum line from the building for the vacuum source, but it would be better to have separate equipment.

However, there is no pressure line in the building, so separate device for air pressure should be needed.

But I’m not sure what kind of table top-equipment will be needed for the pressure of ~10 psi.

I would appreciate it if you could share what source you are using or the product name, if is commercial product.

Thank you.

1 Like

Hi @baelab,

Our building supplies pressurized air and vacuum which can be accessed via valves built into our benches. For the air lines a small compressor will work, which you can drop this down to ~10 psi using something like this:

Vacuum can be supplied in a similar way - we just plugged directly into the house lines, it’s not as necessary to precisely control the vac in our experience.

The code and kicad files for the pressure regulator are on github:

Note there is an issue on the pressure module kicad board that should be resolved soon - BLANK on the PWM board needs to be connected to A0 on the SAMD21 breakout. Also the RS-485 footprint dimensions are slightly off. Both of these things are getting resolved soon.

The standardized SA boards are the same boards used in eVOLVER for PWM and ADC and described in the original NBT paper. They can be purchased from Fynch.

You can download a .ai/.pdf of the millifluidics for the regulator here:

We used these proportional valves:

And these analog electronic pressure sensors:

Last thing to note is that the devices in the original NBT paper were not IPPs, so the comparison at the top of your post isn’t quite 1 to 1. The device you have at the top is actually a multiplexer, not a pump.

I mentioned in your other post - you can probably just use the slow flow rate pumps available from Fynch for chemical inducers and run fewer c-stats/lagoons. Millifluidics are not strictly required to run ePACE.