Low‐Loss Piezoelectric Single‐Crystal Fibers for Enhanced Magnetic Energy Harvesting with Magnetoelectric Composite

Abstract

The concept of magneto-mechano-electric (MME) energy conversion has been demonstrated using a magnetoelectric (ME) composite, with cantilever structure working at resonating mode, to reliably covert low-frequency magnetic noise fields to electric power. [19,20] This process is the result of multiple energy transductions starting from magnetic energy to mechanical energy and then to electrical energy. An MME generator is known to be more efficient than an electromagnetic generator at a small scale in a low frequency magnetic field. A serious of rationally designed MME generators with piezoelectric single crystals had shown great potential for scavenging weak and irregular magnetic energy. [19][20][21][22] The harvesting performance of piezoelectric-based energy harvesters is directly related to the product of the piezoelectric strain constant, d ij and the piezoelectric voltage constant, g ij (the mathematical product of which is called the figure of merit: FOM = d ij × g ij ), under constant applied stress. [19] However, recent investigations have determined that FOM could not explain completely the output performance of such energy harvesters. [19,23] This is because the hysteresis (or non-linearity) of the piezoelectric materials is related to losses such as dielectric loss (inverse of electrical quality factor) and mechanical loss (inverse of mechanical quality factor); and consequently, performance degradation of the device. Therefore, to improve the harvesting performance, it is important to know how the loss factors affect the harvested output power in MME generators.To provide the answer, various piezoelectric PMN-PZT single crystal thin sheets; namely, high-loss PMN-PZT, medium-loss PMN-PZT, and low-loss PMN-PZT with the typical rhombohedral perovskite phase close to the morphotropic phase boundary (MPB), were grown using the solid-state-crystal growth (SSCG) method (see Data S1 in the Supporting information). This greatly improved the desired properties. In this study, we fabricated three MME generators using ME composites with these PMN-PZT single crystalline materials in macro-fibers form, and a magnetostrictive Ni plate. In this paper, the MME generators embedded with high-loss PMN-PZT, medium-loss PMN-PZT, and low-loss PMN-PZT, were identified as highloss, medium-loss, and low-loss (respectively) MME generators. Using them, we eventually succeeded in finding a way to extract significantly improved electric power sufficient to realize a self-powered energy device. Variation in the properties of the piezoelectric PMN-PZT single-crystal macro-fibers (SCMFs) results in a substantial change in the output voltage, the energy harvesting characteristics, and the power density of the device.We are entering an era when electrical energy scavenged from the irregular energy resources that are found ubiquitously in our living environment (e.g., light, vibrations, motion, heat, and magnetic fields) can be used to operate small electronic devices that do extraordinary tasks. [1][2][3][4][5][6][7][8] The needs of th...

Magnetic and Electric Energy Harvesting Technologies in Power Grids: A Review

“…Therein, the most prominent application is to energize wireless sensors [15,16]. For instance, the magneto-mechano-triboelectric generator was designed using piezoelectric and magnetostrictive materials, which convert magnetic noise to useful electric energy applying for low-power consuming electronics or wireless sensor networks [17][18][19]. RF energy could be converted to electric energy through a circuit mainly consisting of an antenna, impedance matching circuit, rectifier, voltage multiplier and energy storage for energizing low-power wireless devices [20].…”

In Vivo Self‐Powered Wireless Transmission Using Biocompatible Flexible Energy Harvesters

“…Recently, our group has demonstrated highly efficient flexible piezoelectric energy harvesters using single crystals for biomedical application . However, the above papers demonstrated the operation of medical devices using in vitro harvested energy from the bending stage.…”

Unleashing the Full Potential of Magnetoelectric Coupling in Film Heterostructures

“…Interfacial coupling between magnetostrictive (MS) (ferromagnetic (FM)) and piezoelectric (ferroelectric (FE)) constituents in multiferroic magnetoelectric (ME) composites results in the electrically and magnetically cross‐coupled devices that are promising for various sensing, transduction, and energy harvesting applications . Film‐based ME composites are required for on‐chip integration of ME devices.…”