Development of new methodologies for the fabrication and actuation of robotic systems

Abstract

This dissertation describes the research that utilizes advanced actuators and unconventional means of fabrication to design and develop dexterous and lightweight robotic systems. It is motivated by a need to advance the current state of the art. The aim is to provide alternative actuation and fabrication methods that combine the use of smart materials, specifically shape memory alloys, with the rapid prototyping technique of stereolithography to develop lighter, multi-articulated robotic systems. Shape memory alloys can be used as actuators due their ability to undergo a shape change at low temperature, retain this deformation until they are heated and then return to their original shape, producing a contraction of the wire. These actuators have the advantages of being lightweight and small in size, while possessing a high force to weight ratio. Stereolithography produces a solid plastic prototype via a manufacturing procedure where three-dimensional solid models are constructed layer upon layer by the fusion of material under computer control. An important aspect of the rapid prototype method used in this research is that multi-articulated systems can be fabricated in one step, without requiring assembly, while maintaining the desired joint mobility. This non-assembly idea is carried a step further, by incorporating components during the build process. The use of shape memory alloy actuators combined with this non-assembly type rapid fabrication will produce agile mechanisms along with reducing their weight and fabrication time. This dissertation illustrates the development of the actuators; the manufacturing of a rapidly prototyped mobile observation vehicle that demonstrates the component embedding process; and the addition of the actuation systems and sensors into an articulated finger model, as the precursor to the rapid fabrication of a smart material actuated multi-degree of freedom robotic hand that largely exemplifies the main ideas of this research.