They used an iron - bearing liquid which they released in small drops at regular intervals at the centre of a dish of silicone oil. (newscientist.com)
Findings showed highly viscous fluids such as silicone oil limit the robot's maximum speed, while low - density media such as air limit how steep they can climb. (sciencedaily.com)
Using this new insight, the team decided to build their own «liquid wire»: a hybrid material made from droplets of silicone oil on a polyurethane thread. (sciencemag.org)