Preparation and electromechanical properties of the chitosan gel polymer actuator based on heat treating

As a new kind of smart materials for fabricating ionic electric actuator, Chitosan Gel Polymer (CGP) known as bionic artificial muscle, has broad application prospects and high academic value with advantages of simple structure, good biocompatibility and large deflection under low driving voltage (≤5 V). In this paper, effects and enhancement mechanism of the heat treating optimization technology on response speed performance of the CGP actuator were mainly investigated. Furthermore, its preparation process including material selection, membrane fabrication and the assembly along with fabrication principle were deeply researched. The CGP actuator consisted of two parts; electric actuating membrane which is sandwiched between non-metallic electrode membranes. On one hand, high viscosity chitosan inside the actuating membrane served as framework which gives access to anions and cations within the electrode membranes. On the other hand, Multi-walled Carbon Nanotube (MCNT) was adopted to modify chitosan in the electrode membrane for obtaining good conductivity and stable chemical character. Moreover, response speed of the CGP actuator that underwent repeated heat treating for a short time, would be continuously improved with the increase of heat treating times. But as the heat treating time prolonged, electromechanical properties of the CGP actuator began to degrade. In addition, since conduction velocity of microscopic ions inside the CGP actuator was presented as macroscopic current magnitude, the experimental results revealed that the changing trend of response speed was almost in accord with the current trend of the CGP actuator. Both of these are fitted in a quadratic function relationship.