Twisted and coiled multi-ply yarns artificial muscles

Artificial muscle plays an interesting role in science discoveries. Large scale torsional and tensile actuation is achieved by twisting and coiling of synthetic polymer fibres. Research reports to date have discussed the theoretical background of actuation of twisted monofilament yarn. Twisting and coiling of several yarns together is another approach to fabricate polymer actuators and here we present the experimental observations of performance of actuators fabricated with multiple number of yarns. The theoretical background for the reasons of decreasing the actuation performance with increasing number of yarns are critically analysed and presented in this study. This analysis concludes that a minor change in the length of the fibre can significantly affect the stroke and force values of the twisted polymer actuators.