DIY syringe and peristaltic pumps are all the rage on the internet. Here are some articles about DIY from the point of view of a software/electronics/maker.
Open-Source Syringe Pump
DIY Syringe Pump : 21 Steps - Instructables
DIY syringe pump usage stepper motor linear actuator
Pumps-cat - SyringePumpPro
Simple Syringe Pumps : 6 Steps - Instructables
DIY syringe pump usage stepper motor linear actuator - RobotDigg
Electric Micro Infusion Syringe Pump Medical Dual-Channel
DIY Syringe Pump Using Stepper Motor : 4 Steps - Instructables
Loading A Syringe on Your Pump - SyringePumpPro
Open-Source Syringe Pump