An eight-armed soft robot’s rhythmic, tentacle-flailing dance routine is so awkwardly cute that you might not immediately grasp the engineering feat achieved by the octopus mimic. Dubbed the “octobot,” it is the first robot to be self-propelled, untethered, and made entirely from soft materials (Nature 2016, DOI: 10.1039/nature19100). Previous soft robots have either had some rigid components or they’ve been attached to a rigid system, explains Harvard University’s Jennifer A. Lewis, who along with colleague Robert J. Wood led the team that built the machine. The achievement helps pave the way for soft robots that can perform search-and-rescue operations or be used in biomedical applications such as endoscopy. The team made the octobot by using a combination of three-dimensional printing, molding, and soft lithography. Hydrogen peroxide fuels the creature: When H2O2 comes in contact with a platinum catalyst, it breaks down into O2 and water vapor that power the robot’s tentacles. Microfluidic logic circuits direct the gases into four of the octobot’s arms at a time, moving half the tentacles out and up with pneumatic pressure. The sequence is then repeated with the octobot’s remaining four tentacles.