[Mohamed Sami] built a syringe pump out of Meccano building set parts. It consists of a simple framework with a DC motor mounted on it that actuates the syringe when powered. A check valve harvested from an ordinary household spray bottle keeps the syringe from sucking back liquid that it has just pumped out, so it can keep pumping forever. A lead-acid battery powers the whole thing.
Syringe pumps are typically used to deliver precisely measured quantities of substances. Right now [Mohamed]’s rig is just an uncontrolled pump, but he hopes to get a better understanding of and control over how much liquid gets pumped. Adding an encoder to the DC motor would be a start, was his thought — or even better would be a stepper.