In a groundbreaking advancement for wearable technology, researchers have unveiled a new hand band capable of delivering watt-level wireless charging, a significant leap forward for mobile devices. This innovative solution, developed by Sangjun Kim and his team at the Department of Mechanical Engineering at The University of Texas at Austin, promises to optimize energy utilization in a variety of settings, particularly in dynamic and potentially hazardous environments typical of the construction sector.
The newly designed hand band utilizes a thin, stretchable format that operates on the widely adopted Qi wireless charging protocol at a frequency of 130 kHz. This design not only facilitates efficient energy transfer but also enhances user safety by eliminating the risks associated with traditional wired connections. “Our goal was to create a versatile solution that could seamlessly integrate into daily activities without hindering movement,” Kim stated, emphasizing the band’s unobstructive nature.
The hand band features a unique protective encapsulation made from non-adhesive fabric, which safeguards a delicate 50-micrometer-thin spiral copper antenna from mechanical strain. This innovation allows for an impressive stretchability of 50%, ensuring comfort and functionality for users. Additionally, the introduction of a stretchable material known as “Ferrofabric” enhances magnetic shielding for the antenna while maintaining wearability. With a magnetic permeability of 11.3 and a tensile modulus of 75.3 kPa, Ferrofabric improves coil inductance, although it does introduce some core loss in alternating current applications.
The research team tackled various loss mechanisms, such as skin effect and joule heating, to achieve a wireless charging efficiency of 71% and a power delivery rate of 3.81 watts. This efficiency allows the hand band to charge a handheld smartphone as quickly as a traditional desktop charger or power a battery-free e-tattoo sensor, which could be particularly beneficial in construction settings where quick access to power is essential.
Kim’s research not only highlights the technological advancements in wireless power transfer but also emphasizes the commercial implications for industries reliant on mobile devices. The construction sector, often characterized by its dynamic environments, stands to benefit significantly from such innovations. The ability to charge devices wirelessly while on the move can enhance productivity and safety for workers, who can now rely on their devices without the encumbrance of wires.
As this technology matures, it could pave the way for further developments in wearable electronics, potentially leading to a new era of smart construction tools and equipment that are both efficient and safe. The research findings were published in ‘npj Flexible Electronics,’ which translates to ‘npj Flexible Electronics’ in English, underscoring the growing interest in flexible and portable energy solutions.
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