The entire project and assembly process is covered in this video: 

To print, you need a machine capable of at least three materials at once. After importing the STL into your slicer, separate the joined STL into individual objects. The base material is PLA or any other rigid filament of your choice. The corners should be a firm TPU. The funny looking ‘locks’ must be dissolvable filament such as PVA.

Please post your makes and remixes to social media so I can see them. I'd love to release a follow up with community 4D printing designs.