New fuel cell harvests energy from microbes in soil to power sensors, communications

A Northwestern University-led team of researchers has developed a new fuel cell that harvests energy from microbes living in dirt.

About the size of a standard paperback book, the completely soil-powered technology could fuel underground sensors used in precision agriculture and green infrastructure.

This potentially could offer a sustainable, renewable alternative to batteries, which hold toxic, flammable chemicals that leach into the ground, are fraught with conflict-filled supply chains and contribute to the ever-growing problem of electronic waste.

To test the new fuel cell, the researchers used it to power sensors measuring soil moisture and detecting touch, a capability that could be valuable for tracking passing animals.

To enable wireless communications, the researchers also equipped the soil-powered sensor with a tiny antenna to transmit data to a neighboring base station by reflecting existing radio frequency signals.

Not only did the fuel cell work in both wet and dry conditions, but its power also outlasted similar technologies by 120%.

The researchers say all components for their soil-based MFC can be purchased at a local hardware store. Next, they plan to develop a soil-based MFC made from fully biodegradable materials. Both designs bypass complicated supply chains and avoid using conflict minerals.

Image source: Bill Yen/Northwestern University.