This clever pneumatic hexapod robot comes out of Okayama University at the Tokyo Institute of Technology. It's a direct printed multimaterial bot with soft interior bladders connected to flexures that control the legs. It's only a few centimeters across, which speaks to the precision of the design and execution. It's truly difficult to get the kind of smooth mechanical action you can see in the video from such small mechanisms.
This is a great example of compliant mechanisms in action, where the bladders are linked to flexures, which control the legs. There is a lot of mechanical complexity here without a large number of components. It's the kind of engineering you find in nature all the time, where material properties flow together to create complex mechanical motion without many hinges or fasteners.