Peristaltic Pumps

So I have been thinking about 3D printing with other materials.  Problem is there is not a whole lot out there on different materials, creamy likey ones, and how to use them.  I stumbled on this article on using a Peristalic Pump to move sludge like material that could be using in “printing.

http://hackaday.com/2013/10/16/3d-printering-pastestruders/