Graphene Nanoplatelet Reinforced Silicone Elastomer Nanocomposites: Mechanical, Electrical, and Electromechanical Actuation Behavior

Artificial muscles based on soft elastomers are increasingly explored for soft robotics, wearable devices, and biomedical systems. Silicone elastomers, such as polydimethylsiloxane (PDMS), are widely used due to flexibility and chemical stability; however, low mechanical strength and limited electrical conductivity restrict electromechanical performance. In this work, graphene nanoplatelets (GNPs) were incorporated into PDMS to develop multifunctional nanocomposites with enhanced mechanical and electrical properties. Composites containing 0–5 wt.% GNPs were fabricated via solution-assisted dispersion followed by thermal curing. Mechanical tests showed tensile strength increased by 45% at 2 wt.% GNP, and Young’s modulus rose from 0.85 MPa to 2.10 MPa compared with pristine PDMS. Electrical conductivity increased by several orders of magnitude with higher filler content due to the formation of conductive networks. Actuation experiments demonstrated the 2 wt.% GNP composite achieved a maximum strain of 10.7%, compared with 8.2% for neat PDMS, and reduced response time from 210 ms to 120 ms. While higher GNP content further improved conductivity, 2 wt.% provided the best balance between mechanical integrity, electrical performance, and actuation efficiency. These results demonstrate the potential of graphene-reinforced silicone elastomers as soft actuator materials and highlight the importance of optimizing filler concentration to achieve multifunctional performance.