I found this video of a 3-D printer being used in the food industry. They are designing a printer that will print anything in a paste form. Can you imagine what you could make with metal clay paste and this machine. I have taught many students to use syringe and I would say that the majority of students I have had struggle with keeping their hand steady. Myself included, I can use paste to entrap a stone and make organic looking details but I have never been able to produce anything that didn't have that "organic" look (when I say organic, I mean imperfect or perhaps even a bit messy).
Here is the video:
The machine is not cost effective but imagine the fun you could have!!!!