Hi there,
This is Bogdan from Romania.
I'm a mechanical engineer, 3D designer and modeler.
I have over 15 years experience designing and prototyping different devices and systems across multiple industries.
I would like to collaborate with you on this project and possible future ones.
While the requirements are achievable (with some difficulties) you will need to provide more parameters: viscosity, discharge head, absorption, etc.
A specialized pump should be designed accordingly with the specific situation where is meant to be used.
As far as I can see, you need this project in two stages: first the design/model of the pump (where to be determined the technical solutions, to be designed the model and find the proper suppliers for components, and second - building the prototype - which is a little more different (the only possible solution for this project is a piston pump, driven through a variable eccentric mechanism, which to allow the variation of the stroke, and an electronic controlled motor to allows the frequency of the strokes).
Any further questions, please just ask...
You may open a chat room here, and we'll discuss all the details.
Regards
Bogdan