Human and animal bodies are efficient because each part serves more than one function: A leg is not only for walking but also stores energy and makes blood cells, for example.

In contrast, robots are normally designed with compartmentalized parts that separate functions.

James Pikul of University of Pennsylvania helped develop a lionfish robot that is powered by “robotic blood”, the first to combine hydraulic force transmission, movement and energy storage into one system.

“We created the robotic fish as a way to show how adding multiple functionalities into robotic parts can dramatically increase their performance and capabilities,” Pikul said.