This thesis presents the study, the modeling and the control of an electrothermal soft actuator. The work begins with a review of the state of the art of different kind of soft actuators and soft robotics, highlighting existing technologies and their applications. The focus then shifts to the modeling and the control of a specific electrothermal soft actuator created by PhD Diogo Fonseca of the University of Coimbra. Then, a mathematical model of the actuator was developed using formulas derived from existing literature and experimental data. This model served as basis for designing and testing different control strategies to optimize actuator performance in a simulation environment.