A team of researchers has developed a fuel cell powered by dirt using microbes naturally found in soil to generate electricity.
The technology could one day offer an alternative to batteries for underground sensors used in farming and environmental monitoring.
The device, created by researchers at Northwestern University, runs on energy released by microbes as they break down organic matter in soil.
Those microbes naturally release electrons during the process and the fuel cell captures that flow to produce small amounts of power.
It is not enough to run phones or laptops, but it can power low-energy sensors, which is exactly what the researchers had in mind.
The team tested the device on sensors that measure soil moisture and that detect touch, which could help track wildlife movement through a field. The system can also send data wirelessly while using very little power.
The idea is partly aimed at solving a growing problem. Modern agriculture relies more on connected sensors to monitor crops, moisture and nutrients.
But powering those devices across large fields is difficult. Batteries run out, while solar panels get dirty, need sunlight and can be unreliable in remote or muddy environments.
“If we imagine a future with trillions of these devices, we cannot build every one of them out of lithium, heavy metals and toxins,” lead researcher Bill Yen said. Instead of bringing power to the sensor, the team wanted the environment itself to become the power source.
Microbial fuel cells have existed in theory for decades, but they have often struggled in real-world conditions, especially in dry soil. The new design changed that.
Researchers redesigned the fuel cell so that one part stays buried in moist soil while another remains exposed to oxygen at the surface. This combination helped it work in both dry and flooded conditions.
The results were strong. The device lasted about 120% longer than similar systems and produced far more power than the sensors needed.
Northwestern researcher George Wells said the goal is practical, not massive-scale energy.
“We’re not going to power entire cities with this energy,” Wells said. “But we can capture minute amounts of energy to fuel practical, low power applications.”
This becomes increasingly important as the Internet of Things continues to expand, with more sensors placed in farms, wetlands and remote landscapes.
Researchers also say the technology could help reduce electronic waste because traditional batteries contain toxic materials and need replacement. A system powered by soil microbes could potentially operate for long periods with little maintenance.
The team is now exploring biodegradable versions built from common materials, which could make the devices even more sustainable.
