This model is a type of micropipette based on single use Pasteur pipettes. I use it to drop small, controlled amounts of silver ink on electronic samples.
You can use the control screws to handle repeatable amounts of liquid or use the high level of control given by the long lever to make small drops of liquid on a substrate.
The suction effect is achieved by the deformation of the plastic membrane under the effect of the plunger. The membrane is maintained via a rubber band which forms an airtight join with the glass.

One device is composed of 1 "handle 1", 1 "handle 2", 2 "plunger" and 2 "pivot"
Except for 3D printed parts you will need:
3 M3 35
2 M3 10
1 spring around 25mm
1 washer
1 elastic membrane (gloves, balloon)

This model is designed for 7mm glass Pasteur pipettes.

A demonstration video is available at:
https://youtu.be/BCXRDhcCiBg