With the rapid advancement of artificial
intelligence, the Internet
of Things (IOT), and metaspace technology, smart wearables have become
increasingly prevalent. These devices incorporate a variety of sensors,
actuators, and signal transmission devices, making the energy supply
a critical factor. It is essential to consider energy sources within
the human body or in the surrounding environment. Mechanical energy
harvesters play a crucial role in the energy supply of smart wearable
devices based on piezoelectric, triboelectric, and electromagnetic
effects. By exploring different modes of mechanical-to-electrical
energy conversion, electromagnetic generators (EMGs) were focused
on in this study due to their high conversion efficiency along with
the ability to generate high current at low voltage and resistive
impedance. The study covered the physical principles, evaluation,
and current designs of electromagnetic generators (EMGs) used to convert
human body motion into electric energy. However, it is worth noting
that despite the advantages of EMGs, their heavy weight, large size,
and complexity have limited their application in wearable electronic
devices. This highlights the need for a future vision of smart wearable
energy harvesters: a miniaturized, high-output, and flexible EMG.
Such advancements would address the current limitations and contribute
to the development of more efficient and practical wearable electronic
devices. The concept of a miniaturized, high-output, and flexible
EMG aligns with the demands of current development and emerging technologies
like nanogenerators.