The properties of polymer gels are between those of a liquid and a solid. Gels are soft materials like liquids but can keep their given shape like a solid. Because of these properties, hydrogels have gained industrial potential, eg, as superabsorbers in diapers or as soft contact lenses, which were developed in the 1970s [1]. Polymer gels can be easily deformed by external stimuli, so that they generate force or execute work on the external environment. If such responses can be translated from a microscopic (ie dimensions of polymer chains) to a macroscopic scale, the conversion of chemical free energy into mechanical work should be realized. As early as 1948, it was found that water-swellable polymer gels can convert chemical energy directly into mechanical work [2, 3]. Since then, such systems were called" chemomechanical systems." These first studies were carried out on polyelectrolyte gels changing their state of ionization [4]. Later, phase transition behavior was also found to occur with nonionized gels [5], The main focus in this direction is the investigation of polymers, which exhibit a lower critical solution temperature behavior (LCST)." Stimuli-responsive,"" intelligent," or, even better," smart" polymers are polymers that respond with large property changes to small physical or chemical stimuli (Fig. 9.1, Table 9.1). The microscopic changes are apparent at the macroscopic level as precipitate formation in a solution or as order of magnitude decrease or increase in hydrogel size and solvent content. These changes are reversible. A lot of research work has been done where temperature, solvent composition, and pH of the smart polymers have …