Effect of the Particle Size and Layer Thickness of GNP Fillers on the Dielectric Properties and Actuated Strain of GNP@PDMS

초록

In this study, graphene nanoplatelets (GNP), a conductive carbon filler, were added to improve the low actuated strain of polydimethylsiloxane (PDMS), which is widely used in DEA. And mechanical properties, dielectric properties, and actuated strain of PDMS composite prepared by adding 0.5, 1,2, and 3 wt% of each GNP were measured. Mechanical properties were measured to be increased as the particle size was larger. In the dielectric characteristics, the higher the aspect ratio of the filler was, the easier the micro-capacitor network in the composite was formed, increasing the dielectric constant, and the higher the GNP contents also led to the increment of the dielectric constant. However, when the loss tangent is high, the performance of the actuated strain decreases because electric energy is converted to thermal energy and leakage current. As a result, the highest actuated strain was exhibited in the M25 composite, and the actuated strain value of 3.01% was measured at low electric field (< 4 kV/mm). In conclusion, it was proved that the composite with GNP with thinner layer and larger particle size, had the highest deformation