Sensors and transducers used in automated control and harsh environments can be protected with a very thin Parylene coating to improve environmental adaptability and reliability, with minimal impact on sensor sensitivity. The usage environment includes freshwater, seawater, refineries, chemical plants, blood and body fluids, as well as radiation environments. There are over 40 million types of sensors protected with Parylene abroad, which can be used for various sensors such as microwave, radio frequency, acoustic, piezoelectric, radiation, chemical, temperature, etc. Among them are automotive sensors, sensors for corrosive environments, biomedical sensors, etc. CMOS devices packaged in Parylene can still function normally after being immersed in seawater for more than 300 days. Using Parylene packaging for protection can even develop microelectronic devices that can be used in liquid nitrogen.