One artist from the Netherlands has created a very unique method of 3D printing, which uses nature as a bonding agent. Eric Klarenbeek has created a 3D printing method which takes ground up straw, infuses it with Mycelium, which is a mushroom/fungus. He then prints an object with the mixture, and no heat. After a day the Mycelium spreads throughout the straw, growing, bonding it together. This creates a cork like material. He then 3D prints a very thin PLA covering to whatever he created, with the straw/fungus mixture and places the mixture inside to let it grow. Below you will see one of this works. Here are further details on this creative process: http://3dprint.com/7279/3d-print-fungus-mycelium/ The prints are extremely strong but also light. Below is one of his 3D printed chairs. Notice the mushrooms growing from it: