Today’s 3-D printers can generally only build things out of one type of material—usually a plastic or, in certain expensive industrial versions of the machines, a metal. They can’t build objects with electronic, optical, or any kind of functions that require the integration of multiple materials. But recent advances in the research lab—including a 3-D printed battery and a bionic ear—suggest that this might soon change.
To read the full, original article click on this link: A Battery and a “Bionic” Ear: a Hint of 3-D Printing's Promise | MIT Technology Review
