Professor Lee Byung-hun at the Department of Biomedical Engineering has developed a wireless power transmission technology that allows Internet of Things(IoT) devices to operate permanently in underground environments—where radio wave penetration is nearly impossible—without the need for battery replacement. The results of research were published in IEEE Transactions on Industrial Informatics, a prestigious international journal in the field of industrial informatics.

Standard Wi-Fi and Bluetooth communications on the surface use Radio Frequency(RF) waves. However, RF waves weaken rapidly when they encounter moisture, soil, or concrete, making it difficult for them to travel deep into the ground. Consequently, the research team focused on the characteristics of ‘magnetic fields.’ Magnetic fields suffer relatively less attenuation compared to RF, making them ideal for underground environments.

"Based on the magnetic induction method, we applied a 'Domino Structure'—arranging coils at regular intervals—to overcome the limitation of short transmission distances," Professor Lee stated. He explained, "By relaying energy at intermediate points, much like placing stepping stones across a river, we could significantly reduce losses and deliver power deep into the earth."

Conventional underground IoT 페스타토토 supply systems primarily involved laying wired cables or using built-in batteries. Wired methods incur high installation costs, while battery-페스타토토ed systems have the limitation of requiring periodic replacement. Previous studies attempting wireless 페스타토토 transmission struggled to perform 페스타토토 transmission and data reception simultaneously, often facing communication losses when supporting multiple devices.

"The greatest strength of this wireless power technology using a domino structure is the ability to provide power and perform data communication simultaneously," said Professor Lee. "The characteristic of supporting multiple devices without interruptions is also unique. Specifically, we minimized signal interference without increasing system complexity through our independently developed 'Load-Resonator Interleaved(LRI)' technology."

The research team verified the stability and sustainability of the technology by installing an 8-stage domino structure in an experimental environment filled with actual soil. The results showed successful stable power delivery of 4V and 160mW to the IoT devices while simultaneously transmitting sensor data back to the surface. Professor Lee noted, "160mW is within the range of power consumption in wireless earbuds, demonstrating the feasibility of long-term underground monitoring without batteries."

The biggest obstacle during research was the control operations of the relay devices installed for power stabilization interfering with the data signals. To solve this, the team devised the LRI(Load-Resonator Interleaved) strategy, which alternates between active sensors(loads) and simple relay coils(resonators). "This method physically clears the path for data, ensuring that power control and data communication do not collide," Professor Lee added.

While previous international studies tended to focus on either transmission distance or data speed, this team's technology holds a significant competitive edge by solving the dual challenges of multi-device support and bidirectional simultaneous 페스타토토 and data transmission within a single system. The simplicity of the structure, achieved without complex circuitry, received high praise from the journal.

The underground wireless power and data transmission system can be applied to various sectors, including Smart Farms, underground infrastructure safety management, and Biomedical fields. "In smart farms, soil moisture and nutrient status across vast fields can be measured in real-time without battery concerns," Professor Lee explained. "It can also be used for infrastructure safety to detect cracks or leaks in underground power tunnels, gas pipes, and water mains." He further noted that since the human body is also an environment where radio waves do not pass easily, the technology can be extended to wireless power supply for implantable medical devices.

The technology is currently at the functional verification stage in a laboratory environment(TRL Level 4–5). Professor Lee stated, "For commercialization, we need long-term reliability tests in irregular environments like actual farms or underground facilities, as well as the miniaturization and packaging of sensor modules. We plan to conduct empirical research in collaboration with relevant companies."

Even from an economic perspective, the impact is substantial. "The biggest economic benefit is lowered maintenance costs," Professor Lee explained. "Previously, heavy equipment was needed to dig up the ground just to replace a battery, but this technology removes the procedure itself." He added that it reduces wiring costs compared to wired methods, eliminates the risk of line disconnection, and lowers device unit prices through a single-switch structure.

Professor Lee revealed that his short-term goal is to secure technical durability by applying the system to smart farm demonstration complexes. Furthermore, he plans to expand into monitoring systems for underground power and communication ducts and continue research to miniaturize the technology into a wireless charging platform for next-generation Brain-Computer Interfaces(BCI) or implantable devices. 

Lastly, Professor Lee emphasized the significance of this research for student researchers. "This achievement is the result of not only master’s and doctoral students but also undergraduate researchers taking the lead in proposing ideas and conducting persistent experiments," he said. "I expect that the participation of undergraduate students in research will lead to even more achievements in the future."