Leonardo da Vinci’s self-propelled cart was designed to use springs as its power source.
Leonardo drew the cart in the Codex Atlanticus around 1478–1480. Two symmetrical leaf springs stored mechanical energy, while a system of gears transferred that energy to the wheels. The front steering mechanism could be preset, allowing the cart to follow a planned route.
The machine is frequently called a robot or the world’s first programmable vehicle, but those labels need care. It was not powered by an engine and could not make independent decisions. Its movement was controlled by stored spring energy and mechanical settings.
A working reconstruction was built for a 2006 exhibition at the Museum of the History of Science in Florence, now the Museo Galileo. Researchers found that the design could operate when built according to Leonardo’s drawings.