Ionic electroactive actuators have shown significant potentials as a artificial muscle for soft robotics due to their large and rapid bending deformation, low power consumption, and safety when stimulated by voltages under 5 V [1–4]. These actuators can be easily integrated into control circuits [3, 5], and are capable of self-sensing [4, 6]. Their actuation mechanism is based on ion currents within an electrolyte membrane driven by the electrical field between two coated electrodes [7, 8]. Consequently, their performance is largely determined by the current density in the electrolyte membranes, which depends on the speed and quantity of ion movement.