UPF_Barcelona

Contribution

This page summarizes the procedure to build a DIY turbidostat and gives some calibration documents that may be helpful for future teams. Our whole philosophy is to promote the open-source hardware movement and that is why we compiled this manual, providing a useful guide for future igemers willing to build a DIY turbidostat. Hope you find it useful!

DIY turbidostat manual

What you will need

Building the device

Making it work

Main parts list:

3D printed piece
Aluminum tube (exterior diameter of 32mm, interior diameter of 28mm, 8cm height)
Methacrylate sheet (laser cut parts, 2 pieces of 4cm x 4cm)
Nuts and screws
Glass wide-mouth bottle (x2)
Glass vial (diameter of 28mm)

Electronics list:

Arduino^TM microcontroller
Breadboard
General printed circuit board
Connection cables
Magnets (x2)
Stirring magnets
Heating resistors (x2)
LED (600nm)
Photodiode
Thermistor
12V fan
Transistor
12V power supply
Peristaltic pump (x2)

1 Design a 3D printing piece for the turbidostat tube holder.

It should have two small holes forming 135º. One hole will correspond to the placement of the LED and the other to the placement of the photodiode. Therefore, the dimensions of these 2 components should be taken into account for the design of the small holes.
Its main hole diameter should match with the exterior diameter of the aluminum tube. And, at the same time, the interior diameter of the aluminum tube should match the glass vial diameter.

Tube holder sketch

Tube holder stl file

2 Laser cut a methacrylate sheet.

Laser cut 1

Laser cut 2

3 Drill the aluminum tube forming the two small holes that will match with the ones from the 3D printed piece.

Aluminium sleeve

4 Perform a hole on a general printed circuit board with a diameter equal to the external diameter of the aluminum tube (32mm).

5 Fix the 2 magnets to the 12V fan with silicone.

6 Assemble the sleeve: put together the 12V fan (with the magnets), the laser cut parts and the 3D printed piece by the insertion of the screws across the mini-holes on corners. Place the aluminum tube and the general printed circuit board. Put the glass vial inside the aluminum tube.

In order to make a working turbidostat, two key areas need to be properly designed.

Electronics module: there are several electronic circuits underlying the turbidostat, all of which are explained in detail in the Hardware page.
Software module: once all the background information about the turbidostat code programming is understood, extensively explained in the Software page, you can check our designed open-source code here.