title: Flexible High-Performance Lead-Free Na0.47K0.47Li0.06NbO3 Microcube-Structure-Based Piezoelectric Energy Harvester.
abstract: Lead-free piezoelectric nano- and microstructure-based generators have recently attracted much attention due to the continuous demand of self-powered body implantable devices. We report the fabrication of a high-performance flexible piezoelectric microgenerator based on lead-free inorganic piezoelectric Na0.47K0.47Li0.06NbO3 (NKLN) microcubes for the first time. The composite generator is fabricated using NKLN microcubes and polydimethylsiloxane (PDMS) polymer on a flexible substrate. The flexible device exhibits excellent performance with a large recordable piezoelectric output voltage of 48 V and output current density of 0.43 μA/cm(2) under vertical compressive force of 2 kgf, for which an energy conversion efficiency of about 11% has been achieved. Piezoresponse and ferroelectric studies reveal that NKLN microcubes exhibited high piezoelectric charge coefficient (d33) as high as 460 pC/N and a well-defined hysteresis loops with remnant polarization and coercive field of 13.66 μC/cm(2) and 19.45 kV/cm, respectively. The piezoelectric charge generation mechanism from NKLN microgenerator are discussed in the light of the high d33 and alignment of electric dipoles in polymer matrix and dielectric constant of NKLN microcubes. It has been demonstrated that the developed power generator has the potential to generate high electric output power under mechanical vibration for powering biomedical devices in the near future.
authors.affiliation: Department of Physics, Indian Institute of Science Education and Research , Bhopal, I.T.I. (Gas Rahat) Building, Govindpura, Bhopal, Madhya Pradesh 462023, India.
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Gupta
authors.affiliation: School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Center for Human Interface Nanotechnology (HINT),and IBS Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University (SKKU) , Suwon 440-746, Republic of Korea.
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Physics & Astrophysics, University of Delhi , Delhi 110007, India.
authors.forename: Binay
authors.initials: B
authors.lastname: Kumar
mesh_terms: D004560:Electricity; D004736:Energy-Generating Resources; D007854:Lead / Q000737:chemistry*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D008855:Microscopy, Electron, Scanning; D009556:Niobium / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D015203:Reproducibility of Results; D012964:Sodium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D010087:Oxides; D009556:Niobium; D007854:Lead; D012964:Sodium
keywords: energy harvesting; ferroelectricity; lead-free piezoelectric; microstructures; piezoelectric generator