SBIR Phase I: Production Optimization of Piezoelectric Fibers to Power Smart Garments

This Small Business Innovation Research Phase I project will focus on the development of a piezoelectric energy harvesting fiber to autonomously power sensors and other low-power electronics in smart garments. This technology will allow the fabrication of garments with seamlessly integrated energy harvesting systems, as opposed to today's rigid electronics, to enable smart garments to move toward the same breathability, fit and comfort as normal clothing. The smart garments market is forecast to continue growing at nearly 20% per year over the next several years, reaching $2 billion by 2018. While there has been significant publicity around the development of smart garments for measuring various physiological conditions of athletes, the broader impact of this technology includes applications for monitoring soldiers, emergency responders and patients where the loss of sensor power (e.g. for body function monitoring or environmental sensing) could be dire. While this project will focus on one particular fiber chemistry, the expected learning that will result in terms of fiber processing and integration into fabric structures will also be applicable to other fiber technologies. The intellectual merit of this project is associated with understanding the behavior of fiber-based piezoelectrics as they are processed into yarns and fabrics. Historically, ceramic and polymer piezoelectric materials are used in rigid or flexible film forms, which are not suitable for the development of wearable textile-based technologies. This effort focuses on a new class of piezoelectric polymer fiber, poly(gamma-benzyl-alpha,L-glutamate) (ePBLG), than can be produced in a single electrospinning process and without the need for physical or chemical post-processing to yield its piezo-activity. The three primary goals of the work will be: understanding the effect of polymer and process conditions on fiber dielectric properties, assessing and optimizing the mechanical and dielectric properties of ePBLG yarns, and evaluating the electrical output of a variety of orthogonal electrodes, as would be appropriate for woven fabric constructions. Through this work we will determine the effects on power output when transforming the ePBLG material into structures required for seamless incorporation into smart garments. With this knowledge, the piezoelectric power supply can be properly sized for the balance-of-system within a specific smart garment design.