A Piezo Smart‐Braid Harvester and Damper for Multifunctional Fiber Reinforced Polymer Composites

The past decade has seen the rapid development of wearable electronics, wireless sensor networks (WSNs), and self‐powered implantable sensors. However, these devices usually require a continuous source of power supply to operate safely and accurately while having the least reliance on conventional battery systems—due to the recharging/maintenance burdens of batteries. Vibration‐based piezoelectric energy harvesting (PEH) from environment, man‐made machinery, and human body movements seems to be a promising solution. Herein, the first integration of a piezoelectric poly(vinylidene fluoride) (PVDF) yarn‐braid microgenerator into a fiber reinforced polymer composite (FRPC) structure is reported. It is demonstrated that the developed smart composite exhibits multifunctional performances, including simultaneous structural (with ≈10% increased Young's modulus), energy harvesting, and vibration damping (with a damping factor of 125%). The results show that an average output voltage of 3.6 V and a power density of 2.2 mW cm −3 can be achieved at strains below 0.15%, under cyclic loading tests between 1 and 10 Hz. Moreover, noticeable improvements are made in the crystallinity percentage and β ‐phase content of as‐received PVDF yarns by, respectively, ≈34% and ≈37%, as a result of the applied coreless radial and axial corona poling techniques.