High performance fully plastic actuator based on ionic-liquid-based bucky gel

In a previous paper, we reported the first dry actuator that can be fabricated simply by layer-by-layer casting, using ‘bucky gel’, a gelatinous room-temperature ionic-liquid containing single-walled carbon nanotubes (SWNTs). Our actuator has a bimorph configuration with a polymer-supported internal ionic-liquid electrolyte layer sandwiched by two polymer-supported bucky-gel electrode layers, which allows quick and long-lived operation in air at low applied voltages. In this paper, we propose a new two-step process using a ball-mill method for preparing the casting solution for the bucky-gel electrode in order to improve the performance of the actuator by developing the bucky-gel electrode layer with a high content of SWNTs which are well dispersed in the electrode layer. We measured the displacement and the blocking force of the new bucky-gel actuator fabricated by hot-pressing the prepared electrode and electrolyte layers and analyzed its experimental results by the tri-layer polymer actuator model which was developed by Alici et al. for conducting polymer actuators. We developed the low-voltage driven solid-state actuator that shows the maximum stress and the strain of 4.7 MPa and 1.9%, respectively, which are comparable with any other low-voltage driven solid-state electroactive polymer actuator technology to our knowledge. The advantage of our bucky-gel actuator is not only in its good performance but also in its easy process in fabrication. The present development provides an important step for electromechanical polymer actuator technologies.