MIT has managed to build a robot that not only builds buildings, but can do so using solar power. Deliver the quarter of a million dollar robot to a work site (or a disaster zone) and it can print out a foam building in less than a day. A foam building may not sound like much, but it would be appreciated in an emergency. A more permanent solution is to print each wall as two foam walls which then act as forms for concrete. The robot can also move slowly, so it isn’t restricted to its reach. Give it enough foam and power (or enough time to soak up enough sun) and it can build entire neighborhoods or larger buildings. If successful, even the house construction industry will radically change.