Bill Yen (EE PhD candidate) has been leading a research effort enabling soil-powered computing and sensing systems. He is the lead author of their recently published paper, 'Soil-Powered Computing: The Engineer's Guide to Practical Soil Microbial Fuel Cell Design.’  Bill led the research effort at Northwestern University in collaboration with Georgia Tech and two University of California schools (UCSD and UC Santa Cruz).

Bill is an EE PhD candidate in Prof. Zerina Kapetanovic’s S4 Lab. Here is how he describes this research:

Imagine a future where we instantly detect the presence of stormwater contaminants or nutrient levels in our farms so we can take timely actions. Internet of Things (IoT) devices have been shown to significantly improve the efficiency of cities and agriculture by providing large amounts of high-quality data. However, IoT sensors are largely restricted to existing infrastructures due to the lack of reliable, decentralized power sources. Batteries run out of power and solar panels are prone to being covered by mud and foliage in difficult environments like green infrastructures and wetlands, and they are also made of heavy metals and toxins that can pollute their deployment site. Soil Microbial Fuel Cells (SMFCs) offer promise as a renewable energy source that is biocompatible and can be made from entirely locally sourced materials. They operate by harnessing the ability of exoelectrogenic microbes to break down organic carbon in the soil, which creates a weak electrical current that serves as the source of power.

Although MFCs have existed as a concept for more than a century, their unreliable performance and low output power have stymied efforts to make practical use of them, especially in low-moisture conditions. Our team spent the past 2 years uncovering barriers to practical SMFC design for powering electronics, resulting in a novel SMFC that operates in dryer soil than previously required. Our design improves the theoretical runtime of SMFC-powered devices by up to 120%, and we used it to build a completely soil-powered wireless moisture and touch sensor, which communicates with a base station through RF backscatter. This project serves as the foundation for perpetual sensing, as SMFCs can continue providing power as long as there is carbon in the soil. We release all of our finalized designs, building tutorials, and simulation tools online so we may open the door for future research to allow SMFC-powered sensors to fill the world’s need for sustainable, self-powered IoT devices.

Congratulations to Bill and team on this extraordinary research!

Read more

• Northwestern Now, ‘Dirt-powered fuel cell runs forever'
• Electronics for you.com, 'Dirt-Powered Fuel Cell Runs Forever.’
• Hackster.io, ‘It’s a Dirty Job, But Somebody Has to Do It.'
• Inceptive Mind.com, 'New dirt-powered fuel cell harvests energy from soil.’
• Independent.co.uk, ‘Scientists invent dirt-fuelled power source that ‘lasts forever.’
• Interesting Engineering.com, 'New fuel cell taps energy from dirt-dwelling microbes to power sensors.’
• New Atlas.com, ‘Dirt-powered fuel cell draws near-limitless energy from soil.'