The nano era, similar to the mid-industrial steel era, not only stands for great technical innovations but also indicates the future trend of existing technologies. It is believed that this period will dominate and transform people’s daily lives. “Nano” is a unit of length deŒned as 10−9 m. To give you an idea of how small it is, the width of a human hair is 106 nm, and the size of an atom is 0.1 nm.