Using chemistry tricks to modify materials, you can print nearly anything. Back in 2002 when I started working at the Cornell Creative Machines Lab, 3D printing was almost exclusively used for making plastic design prototypes. Our lab made some of the earliest attempts to 3D print non-traditional, functional materials. We printed functional electrical batteries by depositing zinc chemical slurries. Later, the lab went on to print functional actuators, transistors, capacitors, and more. This work set the stage for all the other work on printing non-traditional materials, such as tissue and food (below).