Fiber reinforced piezoelectric composites

In this paper, multifunctional carbon fiber composites are fabricated using two different approaches for integrating piezoelectric properties into the composite. The first approach integrates zinc oxide (ZnO) nanorod coated Kevlar fibers into the carbon fiber composite structure while the second approach utilizes barium titanate (BTO) coated carbon fibers. These approaches create composites that exhibit piezoelectric properties while maintaining their mechanical integrity for use in load bearing applications. Low-cost, hydrothermal processes are used to synthesize both vertically aligned arrays of ZnO nanorods and BTO nanowire textured films on the Kevlar fiber's and carbon fiber's surfaces, respectively. These growth procedures allow for the growth on woven fabrics thus enabling simplified composite integration and fabrication. These fabrics are placed between carbon fiber fabrics and molded via a vacuum-assisted resin transfer molding technique to form the bulk composite structure. The piezoelectric properties of ZnO and BTO allow the composites to convert mechanical strain induced from ambient vibrations to electrical energy via the direct piezoelectric effect. To characterize the power harvesting potential of these composites, they are fashioned into cantilevered sections and subjected to accelerations via a permanent magnet shaker. Measuring the voltage output across various resistance loads as a function of base acceleration reveals the power output. This research demonstrates novel approaches to fabricate multifunctional composite systems with piezoelectric and load-bearing properties.