Researchers report GO-based composite fibers as artificial muscles

Researchers at the University of Pennsylvania have fabricated meter-long composite fibers combining graphene oxide (GO) nanosheets with flexible, conductive polymers that can achieve mechanical strength, toughness, and actuation that surpasses biological muscles.

The team wet-spin a mixture of GO nanosheets and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) into a composite fiber in which the flexible, conductive polymer is embedded in between aligned, closely-packed nanosheets. The addition of a depleting agent, polyethylene glycol (PEG), improves toughness and elasticity, while chemical reduction of GO to rGO increases electrical conductivity. Finally, the composite fibers are plied with nylon yarns to create a hierarchical composite actuator with capabilities better than typical biological muscles (75 J/kg work capacity and 924 W/kg power density).