By Efosa Taiwo

Dr. Anabi Hilary Kelechi has successfully developed a long-range wireless power transfer system that could dramatically improve safety and communication capabilities in underground mines during emergencies.

Dr. Hilary Kelechi Anabi from Missouri University of Science and Technology in the United States has designed and tested a system capable of wirelessly powering IoT (Internet of Things) and communication devices from distances up to 35 meters in underground conditions.

The significance of this research lies in its potential to make internet connections faster and more reliable, benefiting millions of users globally. 

By dynamically adjusting network parameters in real time, the AI system adapts to changing environments, ensuring a smoother digital experience. 

Experts believe this breakthrough could reshape the future of wireless technology, paving the way for smarter and more connected communities.

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

The new system could maintain critical communication links during such emergencies by providing power without requiring batteries. The implementation of wireless technology in underground mining environments presents unique technical challenges that differ substantially from surface applications. Radio frequency propagation behaves differently in confined spaces with irregular geometries, high humidity, and conductive ore bodies, creating multi-path effects, signal attenuation, and interference patterns that must be carefully managed.

The innovation uses radio frequency wireless power transfer (RF-WPT) technology with a specialized “Class AB” power amplifier operating in the 880 MHz band. This approach overcomes the significant signal attenuation challenges unique to underground environments, where wireless signals typically experience about 50 dB of power loss.

Dr Anabi tested different signal modulation types and found that frequency modulation (FM) with square carrier waves performed best for power transfer in the underground environment. The harvested energy was stored in supercapacitors, which could then power ESP32 microcontroller units equipped with various communication capabilities.

An innovative aspect of the research was the use of supercapacitors rather than traditional batteries for energy storage. 

Dr Anabi evaluated several options, including 2.5V/25F and 2.7V/100F supercapacitors, finding that while the larger capacity version could store more energy, the 2.5V/25F version charged more quickly—a crucial factor in emergency response scenarios. This approach allows for rapid deployment of power to critical communication systems during the initial stages of a mine emergency.

Dr Anabi also conducted extensive analysis of power consumption profiles for different wireless communication technologies. Their findings revealed that Bluetooth Low Energy (BLE) is significantly more power-efficient than WiFi in these applications, making it the preferred choice for emergency communication systems operating on harvested energy. This insight could influence future designs of mine safety systems, potentially extending operational time during emergencies.

“This is the first long-range wireless power transfer system specifically designed for underground mines at this frequency band. The technology could significantly improve miner safety by ensuring emergency communication systems remain operational even when physical infrastructure is damaged,” Dr Kelechi said.

Beyond mining applications, this technology, it was gathered, has potential implications for other challenging environments where maintaining power to communication devices is critical. Underground infrastructure projects, disaster response scenarios, and remote monitoring systems could all benefit from the ability to wirelessly transfer power over significant distances without requiring battery replacement. The research team is now exploring ways to further extend the range and efficiency of their system for these broader applications.