3D Printable Adjustable Volume Pipette

20,277

164

8

About: father, researcher, engineer, cyclist, and 3D printing enthusiast. I live in beautiful Vancouver, Canada and work at UBC. Many of my hobby projects are also available on thingiverse: http://www.thingiverse....
Pipettes are prolific in laboratories everywhere and used to transfer variable amounts of liquid. Professional tools are calibrated and have dials that allow the user to set the volume. The following instructions are the result of an experiment to develop 3D printable and low cost alternatives to standard lab tools, such as the pipette. This simpler version uses a straw and allows the user to adjust volume using two limit thumb nuts. It should be very useful around any wet lab and works nicely with a relatively high range of possible volume settings. You can calibrate the volume but it is generally only good for low precision work. With the exception of a balloon or rubber glove, spring, straw, and some tape, all the parts are 3D printable without support using a variety of low cost printers. This is a very nice example of alternative lab tools and I hope will contribute to further work in the area. You can also find this model and some user remixes on thingiverse: http://www.thingiverse.com/thing:64977

 

Step 1: Get Everything Together and 3D Print the Pipette Components

Print the upper body, lower body, plunger, and two thumb gears using a 3D printer, the STL files are attached. I printed all the pieces on a Makerbot Replicator 2 at 0.1mm with 15% fill and 100% fill for the plunger.

You will need a spring, which I got from a kids Pez dispenser for its form factor. The balloon membrane or rubber glove is elastic so you may get away without the spring but it is nicer to have it. You also need some tape to seal the gap, and a straw. It is designed for standard straw diameter (which also works with the standard pipette tip) but I can upload others if there is demand, let me know.

Step 2: Make the Membrane

The pipette uses a membrane which is displaced by the plunger and changes the volume in the cavity below allowing for the droplet to be drawn and ejected. Depending on your printer you may need to put some sealant in the cavity and possibly around the membrane, some people have used glue which seems to work fine.

Step 3: Press Together Two Halves.

Hard press the two halves together until fully joined.

Step 4: Cut Away Any Overhang

Use scissors to cut away excess material.

Step 5: Seal the Gap With Tape

Tape worked best for me. I used it to seal the gap and electrical tape has held for months.

Step 6: Insert and Seal Straw

Insert a standard size straw, you may need to add some glue at the interface between the straw and the plastic to seal any gaps. If your pipette does not work as demonstrated in the next step, you may have to go back and make sure there are no leaks either in the cavity with the membrane or at the straw.

Step 7: Test and Calibrate

You can calibrate the pipette using a variety of methods, for example with a balance. I will let you figure out what is best for you. You can see some of the results I have been getting using this tool.

Best of luck!

3D Printing Contest

Second Prize in the
3D Printing Contest

Share

Recommendations

  • Make it Glow Contest 2018

    Make it Glow Contest 2018
  • Optics Contest

    Optics Contest
  • Plastics Contest

    Plastics Contest

8 Discussions

0
None
saintdeces

4 years ago on Introduction

is it possible to make the diameter of the straw bigger? I am trying to settle drops with a diameter of at least 1.5 in.

0
None
Breygon

5 years ago

totally awesome! I work in a lab and use these all three time but the professional ones cost a bomb.... now I just need a 3D printer and I can have my own set!

1 reply
0
None
kwalusBreygon

Reply 5 years ago on Introduction

Thanks, I hope it will help. We definitely use it in our lab for low precision work all the time. If you like it, consider also voting for it.