As part of a class project my group and I had to design and build a way to dispense mustard onto a moving hot dog. The other three groups were responsible for moving buns forward, placing hot dogs into the buns, and dispensing ketchup onto the hot dog. The entire system was fully automated.
My team and I decided to use all high quality material that would be safe to use with foods. Plexiglas plates were held in place by stainless steal rods. They were laser cut to perfectly fit the syringe that was mounted on them. A metal plate was also guided along the rods by a larger threaded rod that rotated by a motor. As the large rod rotated, the metal plate was pushed forward, causing the syringe to compress and dispense the mustard.
Below is a video link:
Note: The video taken was with our first successful run so there was a lot of excitement. Our syringe pump can be seen at the very top lit up by LEDs.