Composite Filaments: MakerBot really pushed 3D ahead this year when it introduced several new composite filaments. These composite filaments combine traditional PLA (polylactic acid) thermoplastic with materials like wood, bronze, iron, and limestone. They can be used to 3D-print objects that look and behave like their real-world counterparts. Wood furniture can be printed, sanded, and stained just like real wood. And it feels like wood too. Metal objects like jewelry, tools, and parts can be printed and polished and look just like their pure-metal cousins. Even the limestone composite filament produces objects that look and feel like real limestone. MakerBots new composite filaments are important because they make it economical to now print in metal, wood, and stone. In the past it was possible to 3D-print in metal, but metal laser sintering was expensive. These new composite filaments make it possible to print objects like a hammer that have both metal and wood parts. The downside is that printing with these new composite filaments requires a unique print head for each type of filament. For most consumers, the cost of an additional

print head to print in each additional material will probably be a minor issue. MakerBots introduction of new composite filaments has the potential to push 3D printing beyond the use of hobbyists, inventors, and manufacturers. A reasonably priced 3D printer that can print more than 50 percent of the objects in a typical household could be a valuable home appliance. Questions 1. Why are 3D printers a potentially disruptive technology to manufacturing? 2. How could new composite filaments affect innovation, prototyping, and new product development?