Flexible Piezoelectric Transducers for Energy Harvesting and Sensing from Human Kinematics

Abstract

This study reports flexible nanocomposite-based piezoelectric nanogenerators (PENGs) fabricated by dispersing various piezoelectric nanoparticles (BaTiO3, ZnO, and PZT) and graphene nanopowder in a silicone matrix. The results indicated that the PZT-based composites showed superior performance in comparison to other ceramics. Subsequently, practical application of PENGs was demonstrated by developing a fully functioning shoe-insole nanogenerator (SING). The SING generated high open-circuit voltage (∼27 V), short-circuit current (429.23 μA), and power density (402 mW/m2) under real-time human walking. Moreover, a facile and inexpensive fabrication method for efficient, skin-friendly, and highly stretchable biomechanical piezoelectric sensors is also proposed. In this regard, multiwall carbon nanotubes/silicone composite stretchable electrodes were prepared to be compatible with the sensors. The electrodes displayed stability even under high uniaxial elongation (100%), and the fabricated sensors responded effectively to almost every joint movement. The results suggested that the fabricated PENGs can be potentially used as self-powered biomechanical energy harvesters/sensors in wearable electronics, haptic sensing, or internet of human-related applications.

Applications of Ceramic/Graphene Composites and Hybrids

“…Graphene-based flexible electronic devices are commonly developed using organics as supporting material. The combination of ceramics and graphene has been reported by Choudhry et al [ 111 ], who mixed distinct piezoelectric ceramics (PZT, BaTiO 3 and ZnO) with GNP into a silicone elastomer matrix to produce flexible nanocomposite-based piezoelectric nanogenerators. The PZT-based material containing 0.5 wt.% of GNP led to the best piezoelectric performance as graphene promoted the formation of nanoelectrical bridges between piezoparticles.…”

Progress on Self-Powered Wearable and Implantable Systems Driven by Nanogenerators

“…chest [78] knee [80,108]; foot [32,48,77] heart and pericardium [87,101,105] pacemaker lead [97,116] elbow [26,56] chest [29,50]; duodenum [120]; stomach [103] knee [26,30,56] neck [18,19,29,50,52] tumor cells [94] lung [86] waist [21,25,27,45,55,74,81] elbow [49,72,76] the surface of bone [99] heart [83,84,86,106,110,114] eye [23,28] wrist [18,29,50] the subdermal dorsal region [93] blood vessel…”

“…skin [17,78] hand [18,37,76] skin underneath [88,92] skin underneath [104] hand [26,33,38,44,53,65] skin [79] Biomechanical Energy Source walking, running [42,53,56,69,80] walking, running [32,48,77] joint movement [99] motions of leg [104] stretching [21,25,26,33,53,56] stretching [29,72] [ 76,79] blood pressure [93] blood pressure [112,119] blinking [23,28] joint movement [49,50,81] the peristalsis of duodenum [120] motions of stomach [103] shake and pat [17,38,43,82] breathing…”

Facile Synthesis of Sprayed CNTs Layer-Embedded Stretchable Sensors with Controllable Sensitivity

“…Wearable electronic devices are getting increasing attention due to their several applications [ 1 , 2 , 3 ]. For such devices, sensors should possess high stretchability and sensitivity.…”