Supervisors: Prof. Alvo Aabloo ja Dr. Mati Arulepp
Opponent: Prof. Edwin Jager, Linköping University, Sweden
A major goal in soft polymeric electromechanical actuator research is to develop a device that operates rapidly with high displacement at low voltage applied, and has low energy consumption at the same time. Current technologies based on electromotors and pneumatic actuators make the final product often too noisy, heavy and too complicated. For that reason a notable demand exist for soft, simple and miniature actuation devices in many technological solutions. For robotics and medical applications a desired actuation source should guarantee steady operation in different environments.
This thesis introduces experiment series carried out for carbide-derived carbon (CDC) based actuator devices in order to study relations between porosity parameters onto generated strain of actuators. In linear actuator configuration the effects based on charge induced volumetric expansion of electrolyte impregnated CDC electrodes were investigated. Test cells with different electrolytes were assembled and electromechanical response was characterized. Dry-type bending actuators which had three layer configuration of two polymer supported carbonaceous electrodes and thin polymeric membrane between them were developed and analyzed. In addition to electromechanical characterization, electrochemical measurements were simultaneously carried out to describe energy consumption of both CDC-based actuators. The studies have pointed out that actuators with gradual displacement/strain characteristics can be prepared from wide selection of precursor carbides available to determine porosity of final carbon material and therefore influence the performance of actuators based on CDC. This unique property together with their facile preparation method, flexibility, remarkable specific capacitance, and low driving voltage enable the CDC-based actuators application in many areas such as artificial muscles, and hybrid actuator/energy conversion devices.