A review on electrospun PVDF-based nanocomposites: Recent trends and developments in energy harvesting and sensing applications

Modern-day requirements for efficient, eco-friendly, and self-powered devices have resulted in a growing interest in piezoelectric polymers among the scientific community. Polyvinylidene fluoride (PVDF) is an excellent electroactive polymer that is flexible, with high mechanical strength, thermal stability, and biocompatibility. The relatively low cost and easiness to be fabricated into thin pliable films made PVDF one of the most studied polymers for the development of nanogenerators and wearable sensors. The piezoelectric properties and therefore the energy harvesting and sensing capabilities of PVDF are distinct characteristics of its electroactive polar phases, especially the β phase. Hence, several PVDF-based nanocomposites that could achieve a high β phase fraction have been widely explored. Electrospinning is one of the best methods for manufacturing such PVDF-based nanocomposite films. This article, therefore, highlights essential information about different electrospinning parameters which help to enhance the β phase in PVDF. The review then progresses into the recent developments and technological advances of electrospun PVDF-based nanocomposite devices in energy harvesting and sensing applications. The piezo-, pyro-, and triboelectric properties of PVDF allow the fabrication of conventional and hybrid nanogenerators. The later can harvest energy simultaneously from multiple sources, sense various fluctuations in their surroundings, and transmit the acquired data immediately when integrated with Bluetooth or wireless devices. They are fine models of self-powered, portable, multifunctional, and sustainable engineering. Finally, a peek into the other possible applications of electrospun PVDF-nanocomposite fibers is also made. Overall, the review aims to illustrate the innovative research and developments of PVDF fiber-based devices and the relevance and prospects they hold as future green sources of energy.