Inspired by a simple children's toy, a jumping popper toy, researchers have unlocked a key to designing more agile and predictable soft robots. Soft robots, made from flexible materials, hold immense promise for delicate tasks, but their complex movements have been difficult to predict and control, especially dynamic actions like jumping. Now, a team from Keio University and The University of Osaka has published a study in Advanced Robotics Research detailing the physics behind the jump of thin hemispherical shells, a fundamental building block for jumping soft robots.