Since the discovery of Carbon Nanotubes in 1991, nanotechnology has come to a new episode. One of the new applications of single walled carbon nanotubes (SWNTs) is to develop high performance actuators. Nanotube actuation mechanism relies on quantum chemical expansion of graphitic carbon lattice if an additional electrical charge was applied. By electrochemical charging and discharging, a motion of carbon nanotubes can be generated. The phenomenon can be easily demonstrated on a free standing film of SWNT buckypaper in an aqueous electrolyte.
In this research, a setup was first established to accurately monitor actuation performance of SWNT buckypaper actuators. From a series of designed experiments, we found that the maximum deformation and applied voltage have a linear relationship. The actuation performance in varied electrolyte was also investigated. For alignment effect of SWNTs, it is the first time that we successfully performed a detailed characterization of the actuation performance of magnetically aligned buckypaper actuators. The aligned buckypaper actuators can demonstrate good response to electrical signal, showing very good repeatability and reversibility. In the experiments of using actuators with different dimensions, we found that larger surface area of SWNT actuators can create more deformation capacity, but it also made the actuator tip deflection unstable. In the high frequency response experiments, all of our SWNT actuator samples demonstrated good response to 1Hz and 10HZ square wave. The tip deflection of SWNT actuators decreased with the increases of electrical frequency. Finally, we developed a SWNT buckypaper/silver paint composite actuator for the first time. It can successfully respond to electrical signals. The results of this research provide essential data and information for further development and optimization of SWNT actuators.
