3-D Printers Spit Out Fancy Food and Green Cars

摘要

Machines that can instantly produce everything from food to flowers are a staple of science fiction. Today do-it-yourselfers have brought the fantasy to life with 3-D printers that lay down thin layers of material, be it plastic or cookie dough, that accumulate atop each other to create any desired shape. The printers, which cost about $1,000, work much like their ink-jet counterparts: A reservoir of material serves as a cartridge, and digital blueprints programmed in advance control the output. The printers can produce objects from model planes to robot toys in layers, in some cases spitting out glue to affix each new layer like frosting on a tiered cake. The technique has been used since the 1980s by manufacturers for rapid prototyping of models and parts.