Legend has it that Lu Ban invented the saw. (Chinese archaeologists have discovered copper saws from the Western Zhou Dynasty in Lantian County and Wugong County, Shaanxi Province in recent years, which are earlier than Lu Ban. Therefore, some people think that the story of Lu Ban’s invention of the saw that has been circulated for many years is unreliable, but this theory is not yet conclusive.)
At that time, the only tool for carpentry was an axe. Lu Ban took his apprentices up the mountain to cut down trees with an axe, which was very laborious and often made him sweat profusely from exhaustion. Once, his hand was broken and blood flowed out. When he saw it, his hand was not cut by an axe, but by a weed leaf. Why are weed leaves so powerful? Lu Ban took a closer look and saw that the leaves were long and had many sharp teeth on the edges.
Lu Ban was deeply inspired, so he made many small teeth on the iron sheet and invented the saw. Using a saw to cut wood is much more convenient and less labor-intensive than using an axe.
In modern times, there is a science called bionics that studies the structure and function of biological systems to improve engineering and technical systems. From this point of view, Luban invented the saw inspired by the shape of weed leaves, which can also be said to be a simple example of bionics applied in practice.