By Efosa Taiwo

Dr. Anabi Hilary Kelechi from Missouri University of Science and Technology has achieved a breakthrough in powering communication devices underground without batteries, potentially transforming emergency response in mining operations.

In a study published in IEEE Access, Dr. Kelechi demonstrated a wireless power system capable of transmitting electricity to devices 20 meters deep within the Kennedy Experimental Mines in Rolla, Missouri.

The system successfully harvested 4.2 volts—enough to operate critical communication equipment during emergencies.

“Underground mines are susceptible to occasional roof falls and cave-ins, temporarily destroying existing wireless communications infrastructure,” explained Dr. Kelechi.

Previous attempts at wireless power transfer underground were limited to just 2 meters due to severe signal loss.

To overcome these challenges, the research team developed a custom system using a military-grade Class A radio frequency amplifier and tested various digital modulation schemes. They found that certain signal formats, including 2ASK, 2FSK, 4FSK, and 8FSK, performed exceptionally well underground, while commonly used surface communication methods like QAM were ineffective.

The study also revealed that traditional techniques for improving above-ground wireless performance, such as multiple antennas (MIMO technology), are ineffective underground.

“There is an absence of multipath effect in underground mines,” noted the researchers, highlighting the unique signal behavior in such environments.

The findings have implications for mine safety and emergency response. This battery-free technology, it was gathered, could provide intermittent power to IoT and wireless sensor network devices, ensuring communication during cave-ins or structural failures when existing infrastructure is compromised.

“The technology is particularly relevant for Nigeria as the country expands its solid mineral extraction industry beyond oil and gas. With underground operations posing safety risks, investing in wireless infrastructure could enhance emergency preparedness and increase productivity,” Dr. Kelechi said.

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