High performance multimaterial fibers and devices

Abstract

Fabricating low energy requiring and self-powered flexible electronic devices can decrease world energy need since energy demand seems to be one of the most fundamental problems in the near future. An excellent solution to overcome this drawback is fabricating functional and energy efficient materials. Fabricating high piezoelectric coefficient materials that are compatible with mass production, easy to produce, low cost and non-toxic is highly demanded in order to design highly sensitive sensors and self-powered devices. This thesis introduces piezoelectric polymer (PVDF-TrFE) based several sensor types, energy harvesting devices such as; prosthetic hand, cardiac sensors, electronic skin, which represent promising device architectures for flexible electronics. Semiconductor, metal, composite, piezoelectric materials or polymers can be drawn by thermal fiber drawing and by applying iterative size reduction technique, the geometry, size and length of fabricated structures can be controlled, which also enables us to design novel in fiber, fiber-array devices at nanoscale. First, to enhance PVDF-TrFE fiber performance, crystallinity of fibers was improved by introducing new designs and phase transition mechanism was investigated in fabricated films and fibers. Finally, conductive composite material for flexible interconnects and electrodes was developed. As a whole, a variety of novel piezoelectric and conductive composite fibers were fabricated by using novel size reduction technique and fiber devices were designed for flexible electronics applications.