Application of reduced graphene oxide- molybdenum disulphide hybrid nano composites to magnetorheological fluid dampers and electromechanical actuators

Abstract

The hybrid nano-composites offer a unique advantage of using the favorable properties of their constituent parts. Whereas, their properties can easily be tweaked by slightly changing the synthetic route. Reduced graphene-oxide (rGO) is a well-known two-dimensional material with supreme mechanical properties. On the other hand, Molybdenum Disulphide $(MoS_2)$ is a member of transition metal dichalcogenides (TMDCs) with semiconducting properties. In the present study, we utilized the supreme properties of $rGO/MoS_2$ hybrid nano composites in smart applications such as magnetorheological fluid (MRF) dampers and ionic polymer soft (IPS) actuators. The iron decorated $rGO/MoS_2$ (magnetic) out- performed (60% better yield stress than CIP) other additives in MRF applications. Moreover, the sedimentation rate was also improved. Similarly in IPS actuators, the $rGO/MoS_2$ composites, owing to the formation of nano-PN junctions (rapid charge transfer) and high charge storage (two Mo oxidation states), displayed exceptional performance (333% higher than rGO). Furthermore, a large bending displacement (4.69 mm) at high frequency (3 Hz) and low voltage (1.5 V) was obtained, which is desirable for future AI based robotic applications.