Electrical engineering

Physics

Electromagnetic coil

Energy harvesting

Magnetic field

Engineering

Voltage

Composite material

Power (physics)

Ferrite core

Materials science

Power cable

Layer (electronics)

Alternating current

Nuclear magnetic resonance

Quantum mechanics

Optoelectronics

ACS Sustainable Chemistry & Engineering

Parasitic magnetic noise arising from an electrical power transmission system is the most abundant form of waste energy in our daily life. In this work, a flexible and rollable magneto-mechano-electric nanogenerator (MMENG)-based wireless Internet of Things (IoT) sensor has been demonstrated to capture and utilize the environmental magnetic noise in the absence of a direct current magnetic field. Free-standing magnetoelectric composites are fabricated by combining magnetostrictive nickel ferrite (NiFe2O4) nanoparticles (∼9 nm diameter) and piezoelectric polyvinylidene-co-trifluoroethylene polymer. The magnetoelctric 0–3-type nanocomposites possess maximum magnetoelectric voltage coefficient (α) of 11.43 mV/cm Oe. Even, without a magnetic bias field, 99% of the maximum α value is observed due to the self-bias effect. The magnetoelectric voltage generation capability under a low-frequency (50–60 Hz) alternating current magnetic field, validated by theoretical simulation, enables the nanocomposite to design efficient MMENG for harvesting a low-frequency stray magnetic field from the power cable of home appliances, such as electric kettle and microwave oven. As a result, the MMENG generates a peak-to-peak open circuit voltage of 1.4 V and output power density of 0.05 μW/cm3 and successfully operates a commercial capacitor under the weak (∼1.7 × 10–3 T) and low-frequency (∼50 Hz) stray magnetic field arising from the power cable of electric kettle. Additionally, under the rolled condition around the power cable, the MMENG generates a slightly improved peak-to-peak open circuit voltage of 1.5 V. Finally, the harvested electrical signal has been wirelessly transmitted to a smart phone to demonstrate the possibility of position monitoring system construction. This cost-effective and easy to integrate approach with tailored size and shape of device configuration is expected to be explored in next-generation self-powered IoT sensors including implantable biomedical devices and human health monitoring sensory systems.

Rollable Magnetoelectric Energy Harvester as a Wireless IoT Sensor