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. (C) 2008 Elsevier Ltd. All rights reserved.