Highly Stretchable Self‐Powered Wearable Electrical Energy Generator and Sensors

Abstract

The ubiquity of wearables, coupled with the increasing demand for power, presents a unique opportunity for fiber‐based mobile energy generator systems. However, no commercially available systems currently exist with typical problems including low energy efficiency; short cycle life; slow and expensive manufacturing; and stiff, heavy or bulky componentry that reduce wearer comfort and aesthetic appeal. Herein, a new method is demonstrated to create wearable energy generators and sensors using nanostructured hybrid polyvinylidene fluoride (PVDF)/reduced graphene oxide (rGO)/barium‐titanium oxide (BT) piezoelectric fibers and exploiting the enormous variety of textile architectures. Highly stretchable piezoelectric fibers based on coiled PVDF/rGO/BT fibers energy generator and sensor are developed. It is found that the coiled PVDF/ rGO/BT enables to stretch up to ≈100% strain that produces a peak voltage output of ≈1.3 V with a peak power density of 3 W Kg−1 which is 2.5 times higher than previously reported for piezoelectric textiles. An energy conversion efficiency of 22.5% is achieved for the coiled hybrid piezofiber energy generator. A prototype energy generator and sensors based on a hybrid piezofibers wearable device for energy harvesting and monitoring real time precise healthcare are demonstrated.

Dynamic Mechanical and Creep Behaviour of Meltspun PVDF Nanocomposite Fibers

“…The BT nanoparticles and rGO can attract PVDF chains, which crystallize on their surfaces in the all-transform due to the interfacial interactions, facilitating the transformation of the local amorphous phase and the α phase into the β phase. In this case, the BT nanoparticles and rGO act as nucleating agents, providing the substrates for the formation of PVDF crystalline nucleation and inducing the formation of the β phase of the PVDF segment via the strong interactions at the interfaces [ 22 ].…”

“…The idea of mixing these two fillers in the PVDF matrix was to take advantage of both these two fillers. The PVDF/rGO/BT coil fiber generated a voltage output of ≈1.3 V and a power density of 3 W Kg −1 under ≈100% strain with the energy conversion efficiency of 22.5% [ 22 ].…”

“…The melt-spun piezoelectric fibers of PVDF, PVDF/BT, PVDF/rGO, and PVDF/rGO/BT were fabricated and discussed in our previous work, and the effects of each these fillers on piezoelectric performance were discussed [ 16 , 19 , 22 ]. In continuation of our previous work, due to the wide range of applications of these high-performance nanocomposite fibers, in this work, the influences of various combinations of PVDF and nanofillers have been investigated on storage modulus and creep behavior.…”

Piezoelectric Nanogenerator Based on Lead-Free Flexible PVDF-Barium Titanate Composite Films for Driving Low Power Electronics

“…There are several strategies followed to achieve the electroactive β phase, such as applying stretching mechanically with heating, applying high voltage, and doping of piezoelectric materials or metallic nanoparticles [19,20]. Mokhtari et al explored the textile architecture and achieved an energy conversion efficiency of 22.5% for the coiled hybrid piezo fiber energy generator [21]. Mokhtari and co-workers tested pizeofibers that were capable of producing a maximum voltage output of 4 V and a power density of 87 µW•cm −3 , which were 45 times higher than earlier reported for piezoelectric textiles [22].…”

Effect of Stretching on Crystalline Structure, Ferroelectric and Piezoelectric Properties of Solution-Cast Nylon-11 Films

“…By utilizing the direct or converse piezoelectric effect, nowadays piezoelectric materials have been widely designed into various smart devices. For example, pressure sensors, wearable electronic textiles and vibrational energy harvesting devices utilize the direct piezoelectric effect, while the shape control and movement actuation count on the converse piezoelectric effect [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ].…”