Thank you a lot for all the suggestion!
I try to explain better my project:
I have 3 bottles with 3 different liquids, and one single empty bottle.
I would like to set a timer where at the end it pumps the first liquid in the empty bottle, then after a couple of seconds, put the liquid back. This for all the 3 liquids, one after the other.
- yes, more than 1 pump can be used, but I want to keep it small.
- I think it's the best way to achieve what I have in mind, but I am open to ideas.
I firstly thought about a peristaltic pump (the ones on Amazon, so I think they are pretty basic), but I didn't know if it was possible to reverse the flow.
Then I thought about a syringe, with a stepper motor that can pull and push the piston, but I think it's not a good way because there is too much liquid to pump (~750mL).