THE FOURTH DIMENSION BY NATALIE HOPE McDONALD 22 JANUARY/FEBRUARY 2016 Today, the term 4D printing may solicit more questions than exclamations, but it essentially refers to 3D-printed objects that have an added dimension-time. These 3D items can actually transform and change shape based upon exposure to certain stimuli, like temperature or water. And while the additive manufacturing technology we may be most familiar with has actually been in existence for more I T I S I N N O VAT I O N Courtesy of n-e-r-v-s-o-u-s A FUTURISTIC LOOK AT THE NEXT GENERATION OF PRINTING A chair that builds itself. A toy that reacts to temperature. A shoe that forms to the foot. Welcome to the new world of 4D printing. The newest technology offers many of the same constructs as 3D, but with a fresh combination of smart materials and conduits that will change how we think about additive manufacturing.