Development and modeling of conducting polymer actuators and the fabrication of a conducting polymer based feedback loop

Abstract

Conducting polymers as a class of materials can be used to build a diverse range of devices. Conducting polymer based actuators (muscles), transistors (neurons), strain gages (muscle spindles), force sensors (Golgi tendon organs), light emitting diodes, photodetectors (eyes), batteries and supercapacitors (energy storage), and chemical sensors (noses) can all be manufactured. The range of behaviors makes conducting polymers the only class of materials that might be able to mimic the full range of functions needed to build a truly lifelike artificial system. In this thesis, a conducting polymer actuator and conducting polymer strain gage are used for the first time to build a reflex or position feedback loop that rejects position disturbances. The successful operation of the conducting polymer based reflex loop is an important step towards building an all polymer reflex loop that is directly integrated into a bulk material. Such a reflex loop could be used to control position, to control force or to dynamically change the material stiffness and viscosity. In the course of the project, an improved understanding of conducting polymer actuators has led to mathematical descriptions of the charging and discharging of long linear actuators and to equations describing the deflection and force of three layer bending beam actuators. These equations can be used as design tools to build actuators that satisfy given performance requirements. Finally, the performance of the actuators has been related to specific material properties to help direct research into new conducting polymeric materials.