Optimization of the Magnetoelectric Response of Poly(vinylidene fluoride)/Epoxy/Vitrovac Laminates

Abstract

The effect of the bonding layer type and piezoelectric layer thickness on the magnetoelectric (ME) response of layered poly(vinylidene fluoride) (PVDF)/epoxy/Vitrovac composites is reported. Three distinct epoxy types were tested, commercially known as M-Bond, Devcon, and Stycast. The main differences among them are their different mechanical characteristics, in particular the value of the Young modulus, and the coupling with the polymer and Vitrovac (Fe39Ni39Mo4Si6B12) layers of the laminate. The laminated composites prepared with M-Bond epoxy exhibit the highest ME coupling. Experimental results also show that the ME response increases with increasing PVDF thickness, the highest ME response of 53 V·cm(-1)·Oe(-1) being obtained for a 110 μm thick PVDF/M-Bond epoxy/Vitrovac laminate. The behavior of the ME laminates with increasing temperatures up to 90 °C shows a decrease of more than 80% in the ME response of the laminate, explained by the deteriorated coupling between the different layers. A two-dimensional numerical model of the ME laminate composite based on the finite element method was used to evaluate the experimental results. A comparison between numerical and experimental data allows us to select the appropriate epoxy and to optimize the piezoelectric PVDF layer width to maximize the induced magnetoelectric voltage. The obtained results show the critical role of the bonding layer and piezoelectric layer thickness in the ME performance of laminate composites.

Status and Perspectives of Multiferroic Magnetoelectric Composite Materials and Applications

“…Preparation of bulk 2-2 laminate composites has been mainly conducted by epoxy bonding and co-firing [5,[22][23][24][25][26]. The most common geometries in laminate composites are either bilayer structure of magnetostrictive and piezoelectric layers or a sandwich structure, whereby the piezoelectric layer is arranged between two magnetostrictive ones.…”

“…This composite structure yielded a giant ME response with an extremely low equivalent magnetic noise. Some polymer-based laminate ME composites prepared using polyvinylidene difluoride (PVDF), a piezopolymer possessing a low ε and a high g, in combination with Metglas or Vitrovac (Fe-based amorphous alloy) and Terfenol-D, have also shown large ME coupling behavior [25,26]. Figure 3.…”

Metallic Glass / PVDF Magnetoelectric Laminates for Resonant Sensors and Actuators

“…Table 1 summarizes the obtained mean magnetic parameters for all the used magnetostrictive alloy compositions [11]. Polymer-based ME laminates are typically produced by epoxing magnetostrictive layers (Metglaslike or Vitrovac; M) to commercial poled β-PVDF (P), following the optimized conditions presented in previous studies [14,15]. All the laminates appearing within this work are bilayers (MP) or three-layer sandwich-like (L-T type, MPM) laminated composites.…”

Flexible magnetoelectric transducer with high magnetic field sensitivity based on Metglas/poly(vinylidene fluoride) heterostructures

“…[14][15][16][17][18] It does not show the above shortcomings of conventional transducers and meet the wearable device demands of being flexible, lightweight, easy fabrication, large scale production and biocompatibility. 19 Actually, flexibility not only provides an additional function during application, but it also enables a more simply integration process on non-planar or even curved surfaces.…”

“…On the other hand, Silva et al reported a PVDF/Vitrovac 4040 transducer which were bonded with epoxies with different elastic moduli to investigate the effect of the bonding layer type. 17 However, in spite of the large ME response, the MPM structure means to add an additional layer of epoxy resin. It will reduce the flexibility of transducers, which may make it not sufficient for a broader area of application.…”