Design and Applications of Piezoelectric Yarns with Olefin Block Copolymer (OBC) Elastomeric Cores

Abstract

This thesis explores the development of a helical auxetic yarn composed of two fibers: (1) a piezoelectric fiber with energy-harvesting abilities and (2) an olefin block copolymer core (OBC) yarn with an optimal combination of strength and elasticity. This yarn would be incorporated into a larger fabric or garment that would eventually take advantage of the mechanical forces exerted by the human body to harvest energy through the piezoelectric effect passively. For this to occur, several factors must be considered. The auxetic nature of the yarn is hypothesized to amplify the mechanical deformation of the piezoelectric fiber, thereby enhancing the overall electric output of the fabric; however, the efficiency and reporting of piezoelectric fiber performance remains unstandardized. A tabulated literature review will show commonalities and trends in presently developed piezoelectric fibers. Additionally, any fabric intended for human wear must be able to withstand the forces exerted by the human body. OBC, with its unique microstructure, may have the correct balance of elasticity and strength required for this task. One option to modify, and hopefully improve, the mechanical properties of OBC is through the use of ionizing particle radiation to cross-link the polymer chains. Considerations for how to mount OBC fibers for irradiation are also included in this thesis, along with an analysis of OBC’s existing mechanical properties.