Electrochemical actuation of carbon nanotube yarns

Abstract

We report on actuation in high tensile strength yarns of twist-spun multi-wall carbonnanotubes. Actuation in response to voltage ramps and potentiostatic pulses isstudied to quantify the dependence of the actuation strain on the applied voltage.Strains of up to 0.5% are obtained in response to applied potentials of 2.5 V. Thedependence of strain on applied voltage and charge is found to be quadratic, inagreement with previous results on the actuation of single-wall carbon nanotubes, withthe magnitude of strain also being very similar. The specific capacitance reaches26 F g−1. The modulus of the yarns was found to be independent of applied load and voltage withinexperimental uncertainty.