Abnormal actuating performance of MXene/polyimide electrochemical actuator in neutral aqueous electrolytes

摘要

MXene exhibits great potential in electrochemical actuators which can convert electrical energy to mechanical motions for applications in smart robots or drug delivery systems, etc. However, the detailed actuating mechanism of MXene in neutral aqueous electrolytes has not been investigated deeply, which may limit its application in wider scenarios. In this work, the MXene/polyimide (PI) electrochemical actuator was fabricated. The unique actuating performance of the MXene/PI bilayer actuator in neutral aqueous electrolytes of K2SO4, Na2SO4, KCl, and NaCl was investigated, respectively. The electrochemical actuating performance depends on the dominant order of ion intercalation and electric double layer under electrochemical stimulus in the neutral aqueous electrolytes. Simultaneously, the effect of the cations on actuating performance was also investigated. The MXene/PI electrochemical actuator exhibits a relative strain of 0.12% in 0.5 mol/L Na2SO4 aqueous solutions, and 82.22% maintenance of the tip displacement after 1 x 10(4 )-cycle stimulation of 1 Hz square wave alternating voltage.