Nonlinear strain-electric field relationship of carbon nanotube buckypaper/Nafion actuators

Due to their large electric field-induced strains and flexibility, carbon nanotube thin film or buckypaper/Nafion actuators can be used in various applications, such as lightweight, low power consuming electroactive materials for morphing structures. However, this material is very new, and only limited studies have been devoted to characterizing and understanding their electromechanical couplings. This paper reports on the study of the conversion mechanism and determination of the current flowing through buckypaper/Nafion actuators driven by electric fields. Experimental results revealed that the saturation of the electrically induced strains of the actuator were due to nonlinear characteristics between the electric field and electric charge behaviours. Moreover, by modeling the electric charge changes versus electric fields, we are able to calculate the strain and current versus electric fields of the actuators. The predicted values were in good agreement with the experimental data. The efficiency of the conversion was calculated and demonstrated to determine the potential of CNT buckypaper/Nafion actuators for smart structure applications. Published by Elsevier B.V.