Modeling, Control, and Self-Sensing of Dielectric Elastomers: from Actuators to Soft Robots

Dielectric elastomers (DEs) are flexible capacitors consisting of a highly deformable dielectric membrane coated with compliant electrodes. DEs can function as actuators converting applied voltage signals into motion, sensors detecting changes in displacement or force based on capacitance variations, or even generators converting external mechanical stimuli into electrical energy. Actuation and sensing can also be performed simultaneously, achieving the self-sensing mode; this enables the implementation of closed-loop control architectures without introducing additional position or force sensors. The unique combination of DE characteristics, which include large deformation, high compliance, high energy density, low energy consumption, low cost, and self-sensing, enables the development of mechatronic actuators and soft robots that surpass conventional technologies in performance. However, the practical use of DE transducers in precise mechatronic and robotic applications is hindered by the strong input–output nonlinearity, which significantly complicates design, modeling, control, and self-sensing. This paper presents an overview of recent advances in model-based approaches and smart algorithms for DE systems. It discusses aspects related to system modeling, design optimization, motion/interaction control, position/force self-sensing, and sensorless control, focusing on engineering applications in the fields of micropositioning actuators and soft robotics.