A dielectric elastomer actuator with a large actuated strain enabled by CaCu₃Ti₄O₁₂/MXene/silicone dielectric composite

Abstract

Dielectric elastomer actuators (DEAs) have garnered widespread attention due to their unique blend of attributes, including high energy density, exceptional efficiency, inherent softness, silent operation, and muscle‐like performance, all of which are highly desirable for soft robotics applications. However, despite these benefits, the practical application of DEAs is hindered by their low dielectric constant and relatively small actuated deformation. In this work, we significantly enhanced the actuated strain of dielectric elastomer actuators by integrating a composite material consisting of CaCu3Ti4O12/MXene/silicone elastomers. We combined conductive MXene nanosheets (MX) synthesized via solution etching technique with dielectric CaCu3Ti4O12 (CCTO) particles. The KH550 is utilized as a coupling agent for the modification of the mixed CCTO‐MX particles. The CCTO‐MXK/PDMS film, with a well‐dispersed 2.5 wt% filling fraction, exhibits a remarkable dielectric constant of 7.91 at 100 Hz, coupled with an outstanding actuated performance of 9.36% at 13.3 V μm−1. These results are instrumental in furthering the fabrication of DEAs with substantial actuated strain, paving the way for advancements in this field.Highlights The CCTO‐MXK/PDMS films, comprising modified CaCu3Ti4O12 and MXene particles along with the KH550 coupling agent, were successfully prepared. The high dielectric constant and sensitivity of CCTO‐MXK/PDMS film were studied. The mechanism of actuated strain enhancement of CCTO‐MXK/PDMS film was analyzed from macroscopic and microscopic levels.