We live in a world of coatings; everything around us from furniture to medical implants and from microscopic to macroscopic objects are coated. The coating is used to change the interfacial properties of the bulk material and acquire it with additional functionalities, such as corrosion inhibition, stability and sensitivity towards specific species. The coating can be as thin as a monolayer or much thicker such as used to protect the ship's hull against biofouling. Today, it is common to describe the coatings as smart, which means that they have more than one functionality or they can respond to an external stimuli, e.g., temperature, pH, etc. There are numerous approaches to prepare coatings either from the gaseous phase, i.e., sputtering, CVD, etc. or from the liquid phase, such as dip- and spin-coating, printing and electrochemistry.