A Low Frequency Mechanical Transmitter Based on Magnetoelectric Heterostructures Operated at Their Resonance Frequency

Abstract

Magneto-elasto-electric (ME) coupling heterostructures, consisting of piezoelectric layers bonded to magnetostrictive ones, provide for a new class of electromagnetic emitter materials on which a portable (area ~ 16 cm2) very low frequency (VLF) transmitter technology could be developed. The proposed ME transmitter functions as follows: (a) a piezoelectric layer is first driven by alternating current AC electric voltage at its electromechanical resonance (EMR) frequency, (b) subsequently, this EMR excites the magnetostrictive layers, giving rise to magnetization change, (c) in turn, the magnetization oscillations result in oscillating magnetic fields. By Maxwell’s equations, a corresponding electric field, is also generated, leading to electromagnetic field propagation. Our hybrid piezoelectric-magnetostrictive transformer can take an input electric voltage that may include modulation-signal over a carrier frequency and transmit via oscillating magnetic field or flux change. The prototype measurements reveal a magnetic dipole like near field, demonstrating its transmission capabilities. Furthermore, the developed prototype showed a 104 times higher efficiency over a small-circular loop of the same area, exhibiting its superiority over the class of traditional small antennas.

Magnetoelectrics: Three Centuries of Research Heading Towards the 4.0 Industrial Revolution

“…Xu et al [ 105 ], developed a low frequency transmitter based on the capabilities of the ME resonance sensor. The ME laminate was composed by a piezoelectric layer (PZT-5A) at the core and a magnetostrictive layer on top and bottom (Metglas).…”

“…The proposed device has successfully demonstrated the generation of an AC magnetic field by driving the piezoelectric phase at the resonance frequency (30 kHz). The device also revealed the capability to act as a receiver antenna [ 105 ]. Keeping focus on the antennas, NanoNeuroRFID is an ultra-compact implantable device composed by a ME antenna array that can harvest electromagnetic energy to power the device, sense quasi-static neuronal magnetic fields as small as 200 pT without direct contact to the tissue, communicate with an external transceiver and works from 10 to 100 MHz, where tissue loss is small [ 106 ].…”

Power-Efficient ELF Wireless Communications Using Electro-Mechanical Transmitters

“…The proposed ELF transmitters generate oscillating B fields by physically moving one or more static field sources. While in principle any type of periodic motion can be used, in practice mechanical challenges restrict the main choices to oscillations or rotations about a single axis [22]- [25]. Here we focus on rotating magnetic or electric dipoles, which have the highest possible field generation efficiency [2].…”

“…In both cases, the authors measured near-field antenna patterns and dependence of signal strength versus distance, but did not discuss data transmission. Other work has demonstrated all-mechanical very low frequency (VLF) transmitters by using piezoelectric elements to produce oscillating electric fields [24], [25]. The generated VLF electric fields have either directly been used to transmit information [24], or coupled to a magnetostrictive material to generate a magnetic field [25].…”

“…Other work has demonstrated all-mechanical very low frequency (VLF) transmitters by using piezoelectric elements to produce oscillating electric fields [24], [25]. The generated VLF electric fields have either directly been used to transmit information [24], or coupled to a magnetostrictive material to generate a magnetic field [25]. These works again pay a great deal of attention to design of the proposed antenna, but do not consider data transmission.…”