An announcement that appeared recently in several media outlets touted that scientists have developed a smart material that, "for the first time," can be programmed to fold itself into complex shapes. The announcement came from Tao Xie, a materials scientist at Zhejiang University in China, and a paper describing the technology was published in Science Advances.
Xie explains in the article that the programming process involves folding the plastic material physically at "various elevated temperatures." That gives the polymer the memory it needs to fold on its own without external forces.
Interestingly, I saw a presentation on a self-folding polymer by Skylar Tibbits, Director of the Self-Assembly Lab at MIT's Department of Architecture, during the Global Plastics Summit in October 2015. I asked Tibbets about this "new" development from the Chinese university and if he'd seen it yet.