Polyurethane-based dielectric elastomers with DBA/BaTiO3 synergistic enhancement and electromechanical actuation for bending and rolling modes

Dielectric elastomer actuators (DEAs) have attracted significant attention in soft actuation technologies. However, traditional dielectric elastomers (DEs) commonly suffer from high actuation voltage requirements and limited deformation responses. To address these challenges, a TPU/DBA/BaTiO 3 dielectric elastomer film with enhanced polarity and flexibility was constructed through solution casting, integrating dibutyl adipate (DBA) as a polar plasticizer, barium titanate (BaTiO 3 ) as a high-dielectric filler, and thermoplastic polyurethane (TPU) as the elastic matrix. Comprehensive characterization by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) confirmed the uniform microstructure and consistent chemical composition of the composite films, with 0.5 wt% BaTiO 3 identified as the optimal loading to achieve homogeneous dispersion and ensure structural integrity. The incorporation of DBA significantly plasticized the TPU matrix, leading to a drastic reduction in Young’s modulus (0.29 MPa) and bending stiffness (0.00025 N·mm), thereby imparting high flexibility and enabling large deformations. Simultaneously, BaTiO 3 nanofillers boosted the dielectric constant to 4782 at 1 Hz, an enhancement attributed to the synergistic effects of DBA-induced dipolar alignment and BaTiO 3 -derived interfacial polarization. The optimized film exhibited a maximum bending displacement of 13.2 mm under 1200 V and retained stable deformation throughout 600 cycles at 1000 V and 1 Hz, evidencing outstanding cyclic durability. Moreover, the addition of 0.5 wt% BaTiO 3 substantially boosted rolling actuation, producing rapid displacement with a velocity of 135 mm·s −1 , which verifies the validity of the synergistic “plasticizer-filler” approach. This work demonstrates that a precise balance between filler loading and plasticizer incorporation is essential for tailoring dielectric and mechanical properties toward high actuation efficiency. Consequently, the TPU/DBA/BaTiO 3 dielectric elastomer provides a versatile material system for flexible actuators with potential applications in soft robotics, wearable electronics, and artificial muscles.