Addressing global challenges such as energy production and storage, climate change, and the aging population requires innovative solutions. Dielectric elastomer transducers (DETs) have the potential to make significant contributions to tackle these issues. They are electrically driven elastic capacitors capable of converting one form of energy into another and can be used as actuators, generators, sensors, and capacitive light-emitting devices. Actuators convert electrical into mechanical energy and have various applications, including valves, pumps, optical lenses, engines, and artificial muscles. Generators convert mechanical or thermal energy into electricity. Sensors convert mechanical deformation into an electric signal. Finally, capacitive light-emitting devices convert electrical energy into light. Although any elastomer can function as a dielectric, enhancing the performance of DETs to be used in various applications requires dielectric elastomers with dielectric permittivity that is as high as possible and carefully tailored mechanical properties. This chapter emphasizes the molecular structure of elastomers and discusses design parameters leading to new materials for DETs with improved performance.