Comparison of K0.5Na0.5NbO3 and PbZr0.52Ti0.48O3 compliant-mechanism-design energy harvesters

Abstract

Piezoelectric energy harvesting from ambient vibrations offers an environmentally friendly approach to powering distributed sensors for the Internet of Things. This paper gives a direct comparison of Pb(Zr,Ti)O 3 (PZT)-and (K,Na)NbO 3 (KNN)-based harvesters using a compliant mechanism harvester design for resonant frequencies of 20, 40, and 70 Hz. At 70 Hz, the measured power densities for PZT-and KNNbased devices are 1139 and 31 μW/mm 3 , respectively, for unimorph structures on nickel foils of 25 and 50 μm in thickness. The power density ratios scale proportionally to the material energy harvesting figures of merit. Energy harvesting with the compliant mechanism design is twice as efficient when compared to harvesting with a simple cantilever beam.

Activation energies for crystallization of manganese‐doped (K,Na)NbO3 thin films deposited from a chemical solution

“…In other work, similar solutions were crystallized using a ramp rate of 10°C/s to process fully crystalline films, as reported elsewhere 21 . KNN films resulting from the solution synthesis and deposition process studied in this paper show promising overall electrical properties and moderate (100) crystallographic orientation at 1 μm thickness 21,22 . In addition, piezoelectric films have been derived from KNN solutions with added stabilizing agents such as polyvinylpyrrolidone 23,24 .…”

“…21 KNN films resulting from the solution synthesis and deposition process studied in this paper show promising overall electrical properties and moderate (100) crystallographic orientation at 1 μm thickness. 21,22 In addition, piezoelectric films have been derived from KNN solutions with added stabilizing agents such as polyvinylpyrrolidone. 23,24 Piezoelectric KNN films with strong (100) orientation, 25 and low leakage current properties by strontium doping 26 have also been derived from chemical solutions.…”

Diffuse multiphase coexistence renders temperature-insensitive lead-free energy-harvesting piezoceramics

“…5 At present, the most widely used piezoceramics in PEHs are Pb-based materials, such as Pb(Zr,Ti)O 3 and PbTiO 3 -BiScO 3 , because of the excellent piezoelectric properties of Pb accompanied by satisfactory temperature stability. 6,7 However, the toxicity of Pb will cause serious harm to the ecological environment and human health, and thus, the search for environmentally friendly lead-free piezoceramics is a top priority.…”

Optimizing Output Power Density in Lead-Free Energy-Harvesting Piezoceramics with an Entropy-Increasing Polymorphic Phase Transition Structure

“…The increasing maturity of 5G technology has promoted rapid development of the Internet of Things (IoTs), which provides excellent opportunities and acts as a driving force for the construction of smart cities, including smart homes, intelligent transportation, and digital medical care. − However, the existing wireless sensors used in IoTs mainly rely on the traditional chemical battery power model, and the related battery lifetime problems and replacement costs have led to an urgent need for the development of new alternative power technologies. Piezoelectric energy harvesters (PEHs) represent a feasible solution to drive these wireless sensors, which can convert the mechanical energy that can be found everywhere in daily life into electrical energy, regarding as one of the most promising potential power technologies for the 5G era. − To date, the most commonly used materials for PEHs are still largely Pb-based materials, , which can cause serious damage to the environment and to public health. In recent years, there have been reports of lead-free PEHs, , but the low output power density of these devices still presents a bottleneck that restricts their practical application …”