Hollow piezoelectric ceramic fibers for energy harvesting fabrics

Abstract

In the past few years, the growing need for alternative power sources has generated considerable interest in the field of energy harvesting. A particularly exciting possibility within that field is the development of fabrics capable of harnessing mechanical energy and delivering electrical power to sensors and wearable devices. This study presents an evaluation of the electromechanical performance of hollow lead zirconate titanate (PZT) fibers as the basis for the construction of such fabrics. The fibers feature individual polymer claddings surrounding electrodes directly deposited onto both inside and outside ceramic surfaces. This configuration optimizes the amount of electrical energy available by placing the electrodes in direct contact with the surface of the material and by maximizing the active piezoelectric volume. Hollow fibers were electroded, encapsulated in a polymer cladding, poled and characterized in terms of their electromechanical properties. They were then glued to a vibrating cantilever beam equipped with a strain gauge, and their energy harvesting performance was measured. It was found that the fibers generated twice as much energy density as commercial state-of-the-art flexible composite sensors. Finally, the influence of the polymer cladding on the strain transmission to the fiber was evaluated. These fibers have the potential to be woven into fabrics that could harvest mechanical energy from the environment and could eventually be integrated into clothing.