Inverse Magnetostrictive Effect in Fe₂₉Co₇₁ Wire/Polymer Composites

Abstract

Wearable Internet of Things devices require innovatively designed electromagnetic materials and energy harvesting technology that is lightweight and able to withstand vigorous exercise and impact. In this study, magnetostrictive wire/polymer composites are developed for the first time by embedding Fe-Co wires in an epoxy matrix, and their inverse magnetostrictive characteristics are studied. The output voltage of this novel composite due to compression dramatically increases with increasing stress-rate. Synthesis of the Fe-Co wire-based composite may induce tensile prestress (rather than compressive prestress) during curing, leading to an extraordinary inverse magnetostriction enhancement. This work opens the door for development of lightweight, robust, and efficient energy harvesting devices.The Internet has more than two billion users worldwide, and user experiences and quality of life can be further improved by allowing seamless communication among various physical devices. Internet of Things is the enabling technology for a plethora of long-awaited applications and business opportunities in fields such as domotics, e-health, and real-time monitoring. [1] Energy harvesting is an emerging technology that has been recently receiving much attention as an alternative proactive method to power wireless communication nodes; there have been many studies conducted on energy harvesting from sources such as vibrations and motion resulting from direct force inputs.

Stress-Rate Dependent Output Voltage for Fe₂₉Co₇₁ Magnetostrictive Fiber/Polymer Composites: Fabrication, Experimental Observation and Theoretical Prediction

“…This work opens the door for development of lightweight, robust, and ef cient sensor and energy harvesting materials. 8) and Galfenol bulk 8) .…”

“…Third, because of the high aspect ratio of the bers, the effect of the demagnetization elds is effectively reduced. Figure 3 shows the scanning electron microscope (SEM) images of the surfaces of the Fe 29 Co 71 ber, Fe 29 Co 71 wire 8) and Galfenol bulk. A strong texture can be found in the ber.…”

“…On the other hand, Fe-Co alloys can be good candidate magnetostrictive materials applicable to the energy harvesting devices due to their abundance and lower cost compared with Terfenol-D and Galfenol. Recently, magnetostriction of Fe 1−x Co x (x = 50-90 at%) alloys prepared by forging and subsequent cold rolling was studied for various alloy compositions and thermomechanical treatments by Yamaura et al 7) Fe-Co alloys exhibit high strength, ductility, and excellent workability, allowing easy fabrication of Fe-Co wires, and Narita 8) developed the magnetostrictive wire/ polymer composites that exploit the characteristics of Fe 29 Co 71 wires with diameter of approximately 1 mm, and elucidated the stress-rate dependence of the output voltage of the composites due to compression.…”

A Review on Piezoelectric, Magnetostrictive, and Magnetoelectric Materials and Device Technologies for Energy Harvesting Applications

“…Synthesis of this composite may generate tensile, rather than compressive, prestress during curing, leading to a remarkable inverse magnetostrictive property enhancement. [121] Copyright 2017, Wiley-VCH. As shown in Figure 21, seven LEDs are lit up by the prototype.…”

“…Output voltage density versus stress rate and maximum stress for a) Fe 29 Co 71 wire/polymer composites with prestress σ 0 ¼ 0, 2.8, 5.6, and 11 MPa and b) Fe 29 Co 71 wire/polymer composite with σ 0 ¼ 2.8 MPa and Galfenol [121]. Copyright 2017, Wiley-VCH.…”