In technology, an improvement to something already existing. Distinguishing an element of novelty in an invention remains a concern of patent law. The Renaissance was a period of unusual innovation: Leonardo da Vinci produced ingenious designs for submarines, airplanes, and helicopters and drawings of elaborate trains of gears and of the patterns of flow in liquids. Technology provided science with instruments that greatly enhanced its powers, such as Galileo's telescope. New sciences have also contributed to technology, as in the theoretical preparation for the invention of the steam engine. In the 20th century, innovations in semiconductor technology increased the performance and decreased the cost of electronic materials and devices by a factor of a million, an achievement unparalleled in the history of any technology.