Scientists have been trying to build snakelike, limbless robots for decades. These robots could come in handy in search-and-rescue situations, where they could navigate collapsed buildings to find and assist survivors. With slender, flexible bodies, limbless robots could readily move through confined and cluttered spaces such as debris fields, where walking or wheeled robots and human rescuers tend to fail. However, even the most advanced limbless robots have not come close to moving with the agility and versatility of worms and snakes in difficult terrain. Even the tiny nematode worm Caenorhabditis elegans, which has a relatively simple nervous systems, can navigate through difficult physical environments. As part of a team of engineers, roboticists and physicists, we wanted to explore this discrepancy in performance. But instead of looking to neuroscience for an answer, we turned to biomechanics. We set out to build a robot model that drove its body using a mechanism similar to how worms and snakes power their movement. Undulators and mechanical intelligence Image: NASA Over thousands of years, organisms have evolved intricate nervous systems that allow them to sense their physical surroundings, process this information and execute precise body movements to navigate around obstacles. In robotics, engineers design algorithms that take in information from sensors on the robot’s body – a type of robotic nervous system – and use that information to decide how to move. These algorithms and systems are usually complex. Our team wanted to figure out a way to simplify these systems by highlighting mechanically controlled approaches to dealing with obstacles that don’t require sensors…Worm-like robots will soon assist future search and rescue teams