Wireless energy transfer based on strain-mediated composite multiferroics

Abstract

A subclass of magnetoelectric composite multiferroics can bi-directionally couple AC electric fields with AC magnetic fields using mechanical strain as a mediator. Serendipitously, AC electric fields, AC magnetic fields, and vibrations, are the mediums used in capacitance-, induction-, and acoustic-based wireless energy transfer (WET), respectively. As a result, strainmediated composite multiferroics are uniquely positioned to transform all these modes of WET. This paper analytically and experimentally reports the ability of composite multiferroic hollow cylinders to wirelessly transfer energy to and from laminated multiferroic plates by the use of AC magnetic flux as an energy carrier. In all, the composite cylinders in conjunction with laminated plates are successfully demonstrated as a novel technology of bi-directional magnetoelectricbased WET. We report a peak extracted power of ∼100 μW, which is enough to wirelessly power a multitude of small electronic devices.

Insights into the displacement field in magnetoelectric composites

“…For example, our previous experimental investigations have mostly emphasized the converse magnetoelectric response in the circumferential direction granting particular interest to modes that maximize the circumferential deformation of the inner magnetostrictive ring. The 8.33 kHz of the two-lobe, out-of-plane flexural mode and 29.7 kHz of the radial expansion mode are closely related to the two previously experimentally observed peaks in the converse magnetoelectric response, discussed in Newacheck and Youssef (2019) and seen in Figure 2, with a minor peak at ;9 kHz and a major peak at ;31 kHz, respectively. Our prior investigation of the same composite cylinder structure reported the maximum CME response at the major peak of ;31 kHz, which also correlates to the resonant frequency of the composite noted in the harmonic analysis section, besides being the closest to the in-plane radial expansion as discussed above.…”

Long-Term Converse Magnetoelectric Response of Actuated 1-3 Multiferroic Composite Structures

“…In other words, the quality of the bonding layer was compromised at the crack site, which reduced the efficacy of strain transduction and resulted in a lower CME. The poor strain transfer at the crack site was consistent with the predictions of the effective medium theory and previous experimental investigations [5,12,13,[17][18][19]27,34,35]. A final note about the first observed behavior of the CME is warranted since it is counterintuitive to expect any strain-mediated coupling whatsoever at the crack site given the reasons regarding interface quality and the dependence of transduction efficacy of the continuity conditions, as discussed above.…”

“…Interestingly, Newacheck et al recently discovered an extended frequency-modulated operation range of concentric multiferroic cylinders beyond the magnetic field required to achieve the peak piezomagnetic response and magnetic saturation [17]. The culmination of these studies provides the experimental validation of the standing hypothesis by Bichurin and Viehland regarding cylinder structures outperforming their 2-2 laminated plate counterparts [12][13][14][17][18][19].…”

“…The sample was continuously loaded, electrically and magnetically, over 45 days with a DC magnetic field of 500 Oe and a simultaneous AC electric field of 20 kV/m at a frequency of 32.5 kHz to study the long-term performance of the multiferroic cylinder composite structure. These conditions were selected based on a priori experimental studies [12][13][14][17][18][19][20][27][28][29]. The sample was held in place using a 3D-printed mount that was centered perpendicularly between the two poles of an electromagnet.…”

Noncontact spatiotemporal strain mapping of composite multiferroic cylinders

“…A promising geometry for magnetoelectric composites is a concentric cylinder, where an outer piezoelectric layer surrounds an inner magnetostrictive layer. This geometry, for the first time, has been recently demonstrated in wireless energy transfer (Newacheck and Youssef 2019a), notably both transmitter and receiver elements were multiferroic structures, and also has potential in actuation applications (Mushtaq et al 2019). Analytical models predict the concentric cylinder geometry to exhibit a giant magnetoelectric response due to the curvature enhancing the strain transfer between material layers (Wang et al 2010a).…”