Artificial muscle based on coiled CNT yarns and biofriendly ionogels

A contractile ionic electrochemical actuator was designed by incorporating two coiled carbon nanotube (CNT) yarns coated with a biofriendly ionogel. The working principle of such an actuator stands in capacitive ionic accumulation at the electrochemical double layer, which converts into linear contraction of the coiled CNT yarns. The prepared ionogel showed a good ionic conductivity of up to 1.9 mS cm-1 at room temperature and suitable mechanical properties (Young modulus <1 MPa and elongation at break at 75%). The ionogel/coiled CNT yarn actuator exhibited a maximum contractile stroke of 1.78% under electrochemical stimulation in open air. Such yarn actuators with safe components could open opportunities for application prospects in smart textiles and biomedical devices.