Chocolate on demand. A Philadelphia business built a 3-D printer that prints chocolate. Cocoa Pick what type of chocolate you want to use, pick a design, throw your SD card in the printer, stand back, and watch your edible creation come to life. The idea for Cocoa Press was born when Evan Weinstein was in high school when he built his first prototype in a robotics class. After 4 years of tinkering with the idea at the University of Pennsylvania, it has grown into a start up business run out of the University's Pennovation Center.