Local Magnetoelectric Effect in All-Printed Magnetorheological Elastomer-Piezoelectric Polymer Layered Structures

A fully printed magnetoelectric (ME) layered composite has been developed, leveraging the stress-mediated response in the piezoelectric layer of the structure, comprising a magnetorheological elastomer (MRE) and a piezoelectric PVDF-TrFE layer. The MRE layer is fabricated using direct ink writing, whereas the piezoelectric ink, formulated using green solvents, was printed on top via inkjet printing. The ME effect was characterized on the nanoscale using piezoresponse force microscopy (PFM). PFM spectroscopy measurements were conducted in the absence of a magnetic field and with the application of a 40 mT magnetic field. The ME effect manifested in an asymmetric increase of the coercivity, observed in the phase hysteresis loop, that shifted 27.3 V in the positive region and 31 V in the negative region. The amplitude response was reduced, suggesting that the magnetoactive phase pins the polarization domains and hinders their rotation. The ME coefficient was estimated to be between 31 and 91 V cm –1 Oe –1, which is remarkably high for a composite. The verification of the ME response at the nanoscale, driven by the coupling of an MRE and a piezoelectric polymer, opens up possibilities of designing ME devices due to the versatility of the additive manufacturing techniques.