Almost all scientific inventions and innovations are for the benefit of mankind and the convenience of life. In the same decades, with the efforts of scientists, we no longer have to worry about preparing all kinds of clothes for the change of seasons, unless it is simply for fashion and trendy. Recently, fashion designers are developing a "smart coat". This "smart" coat can be worn all year round, because it can adjust the temperature suitable for human body according to the change of external temperature.