Scientists at MIT are using a new technique that could print responsive objects—from water pipes to sneakers—that adapt to their surroundings on their own.These days, 3D printing seems to be at the core of most new new research ventures, whether it's developing ways to print entire meals or recreating facial features to repair a patient's face. But Skylar Tibbits wants to up the ante: He's hoping 4D printing will be the thing of the not-so-far future. The name for his concept, Tibbits admits, was a bit lighthearted at first. At the Massachusetts Institute of Technology, Tibbits and researchers from the...