Skylar Tibbits and his team at MIT's Self Assembly Lab are working on programmable materials to create 4-D printing. What exactly is 4-D printing? The Self Assembly Lab works to create physical objects that can self-construct from stored memory inside their materials, adding what is commonly referred to as the 4th dimension — time — to 3-D printing. It may sound like the stuff of science fiction, but Skylar was inspired by similar self-producing, self-constructing organisms in nature.