New dirt-powered fuel cell could run forever

According to the researchers, the completely soil-powered technology could fuel underground sensors used in precision agriculture and green infrastructure.

This 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 track passing animals. To enable wireless communications, the researchers equipped the soil-powered sensor with a tiny antenna to transmit data to a neighbouring 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 per cent.

In a statement, Northwestern alumnus and study lead, Bill Yen, said: “The number of devices in the Internet of Things (IoT) is constantly growing. If we imagine a future with trillions of these devices, we cannot build every one of them out of lithium, heavy metals and toxins that are dangerous to the environment.