"A new phase-changing material built from wax and foam developed by researchers at MIT is capable of switching between hard and soft states."
MIT researchers are trying to change the paradigm of your typical robot by mimicking organic substances. The idea is that the robot should be soft to conform to a particular environment, and interact with humans, though rigid enough to actually do a procedure. They can achieve this by applying heat at particular points to deform the object, then applying coolness to make the object rigid again.
"Robots built from this material would be able to operate more like biological systems with applications ranging from difficult search and rescue operations, squeezing through rubble looking for survivors, to deformable surgical robots that could move through the body to reach a particular point without damaging any of the organs or vessels along the way."