The sun was sparkling on the Mediterranean Sea on the afternoon when a graduate student from my lab tossed our prize robot into the water for the first time. I watched nervously as our electronic creation sank beneath the waves. But the bot didn’t falter: When we gave it the command to swim, it filled its expandable mantle with water, then jetted out the fluid to shoot forward. When we ordered it to crawl, it stiffened its eight floppy arms in sequence to push itself along the sandy bottom and over scattered rocks. And when we instructed it to explore a tight space beneath the dock, the robot inserted its soft body into the narrow gap without difficulty.
As a professor at the BioRobotics Institute at the Scuola Superiore Sant’Anna, in Pisa, Italy, I lead a team investigating soft robotics. This relatively new field of research has the potential to upend our ideas about what robots are capable of and where they can be useful. I chose to build robots that mimic the form of the octopus for two reasons. First, because they’re well suited to demonstrate the many advantages that come when a machine can flex and squish as needed. Also, it’s an excellent engineering challenge: An octopus with eight wiggly arms, which must work together in the face of complex hydrodynamic forces, is very difficult to design and control.
In the course of our research, my team hoped to provoke a fundamental rethinking of robotic theories and techniques. We wanted to showcase materials that could be used in actuators that bend and stretch. More crucially, we sought to develop strategies for operating a robot that can curl its limbs in any direction, making it far more tricky to control than a rigid, articulated robot with limbs that have just a few degrees of freedom. To address these challenges, we drew inspiration from nature’s design of the remarkable flesh-and-blood octopus.
Up until recently, robots have mainly been used in factories, where their rigid arms are well suited for the repetitive tasks at hand and the accuracy required. Now, however, roboticists want to put their creations to work in more unpredictable settings where conventional robots often run into trouble.
Some researchers want to build flexible robots that can navigate irregular landscapes, like the ocean floor or the surface of Mars. These robots must move over rough terrain without getting stuck and need manipulators that can grab whatever strangely shaped objects they encounter. Other researchers are focusing on soft robots that can be trusted not to hurt the people they come into contact with. Such soft robots could, for example, work as aides for the disabled or the elderly, and miniature soft robots could even serve as surgical tools inside the body.