There is a long existing gap between the traditional, forceful yet ponderous actuators and the compliant but powerless soft actuators. Despite significant effort to create artificial muscles from rigid or soft materials, none has outperformed biological muscles that can achieve actuation strain (&gt;40%), work capacity (40 J/kg) and power density (100-500 W/kg) simultaneously. Here, we demonstrate scalable fabrication of 10-meter long liquid crystalline (LC) reduced graphene oxides (rGO)/conducting polymer composite fibers as artificial muscles by wet spinning the LC graphene oxide (GO)/ poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) co-dispersion into a coagulation bath. To obtain the close-packed GO sheets, water extraction speed, ionic interactions and depletion force are fine-tuned. The GO/PEDOT:PSS fibers are chemically reduced to rGO/PEDOT:PSS fibers with high electrical conductivity of 212 S/cm. Scanning electron microscopy (SEM) and small-angle X-ray scattering (SAXS) images confirm the closely packed brick-and-mortar assembly of rGO sheets and PEDOT:PSS. As a result, the rGO/PEDOT:PSS fibers can achieve both large tensile modulus (1.2 GPa) and outstanding toughness (3.85 MJ/m<sup>3</sup>). When they are plied with non-conductive nylon fibers, we create strong (work capacity, ~ 48 J/kg) and fast (response time, ~80 ms) electrostatic-based actuators yielding a power density of over 500 W/kg, similar to that of biological muscles. When threading the fibers into a robot body, we demonstrate electrically actuated walking and flying robots.

Ultra-fast and strong electric artificial muscles from hierarchically assembled liquid crystalline reduced graphene oxide-conducting polymer composite fibers

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.