MudWatt – the Microbial Fuel Cell STEM kid – generates electricity from bacterial poop! Yes, really! The soil under your feet hosts a clean, sustainable source of energy. Geobacter sp. and Shewanella sp., soil bacteria, “poop” electricity. You select the soil, set up the unit, download the app, and wait for the LED to begin blinking. As the number of bacteria increase, the LED blinks faster. The app records and graphs your MudWatt energy, predicts and graphs bacterial populations, and unlocks cool facts and a graphic novel to teach what’s going on.
Capture the Waste!
Electrogenic bacteria can be found naturally in soils all over the world. If the soil is stinky, you’ve found Shewanella and Geobacter having a party. In addition to giving off electron “waste” some electrogenic bacteria release stinky sulfur compounds. Think of the rotten-egg smell of mud in a swamp or marsh. I found a pot of daffodil bulbs that didn’t drain properly and started to rot. The stink immediately made me think of healthy populations of Shewanella and Geobacter. That stinky soil will get our MudWatt MFC working quickly this weekend.
MudWatt – A DIY Microbial Fuel Cell
Want to do your own MFC experiments? The MudWatt is a fantastic STEM education kit has everything you need to make your own MFC using whatever soil and experimental conditions you choose. The basic kit includes electrodes, a chamber with lid, graphite pad, led light, and other necessary equipment. You decide what soil to use, what “special ingredients” to add, and other conditions such as temperature.
The MudWatt kit and the subsequent business Magical Microbes was inspired and developed by Keegan Cooke from the educational outreach work he did. In 2010, he was a scientist in a private company working on developing MFCs at the ocean bottom for military use. Seeing kids eyes light up and fielding their many questions when he took “buckets of dirt that lit lights” out to educational events, Keegan knew there was a need for this science kit. He teamed up with an engineering friend, Kevin Rand and they started tinkering. Karen Manning created the OUTSTANDING accompanying educational materials!
Tested and Retested: Home and Outreach
In 2017 Magical Microbes sent us a Science Fair kit (the 3 MudWatt kit) that my kids, playdates, and fellow moms have experimented with. Do the MudWatt bacteria grow faster with granular or powdered sugar? White or brown rice? Compost or soil from the yard? A friend borrowed the kit for an elementary school STEM night and set up yard soil versus commercial topsoil. Since 2017, I’ve used those 3 kits time again for outreach with preK-12 students, STEM club/STEM nights, and Girl Scouts. I purchased the Science Fair kit for my nieces to experiment with as a summer project.
Classroom Use: In-person and on-line
MudWatts – a safe, intriguing, “hands-on” demo or assignment for classes! For my General Microbiology class, I set up 3 MudWatts using mud from the same locations, but at different temperatures. Then show the graphs of population growth and energy output to the students. We discuss what abiotic factors (temperature, light, pH, oxygen, nutrients, etc..) might be causing the different growth profiles and energy output. During 2020 on-line classes, MudWatts were part of a “Micro at Home” kit for students to set up and monitor. I still have one functioning unit in my office since that Fall 2020 class. I just water it once a month and the light keeps blinking – slowly, but steadily.
Girl Scouts “GET MOVING” with MudWatt
Jac’s new Junior Girl Scout troop is doing the “GET MOVING” journey this fall to study different types of energy and energy conservation. For a few meetings, the girl’s will set up MudWatt experiments to optimize their energy production! I can’t wait to see what soils they decide to use and/or ingredients to add. What conditions will produce the most energy? What other findings might they make? Stay tuned for how that goes. Similar to the GET MOVING journey, Keegan’s goals with MudWatt, DoughLab, and future Magical Microbes kits are to excite kids about the fun and creativity in science and engineering, while connecting to their local environment.
We want kids to see that science and engineering is fun, and inherently creative. We want them to see that there is still magic in the world (right beneath their feet) which can be explored through science and engineering. And we want them to develop an empathy for the environment and show them that the environment (even dirt) is a living system that must be taken care of. – Keegan Cooke, CEO and founder of Magical Microbes
Keegan related one example of Ricky, a kid in California, who using soil from his local river in his MudWatt, produced twice as much power as the Magical Microbes Team had ever produced in their lab! Ricky and his dad found out a waste-water treatment plant upstream might have released additional nutrients into the river. That’s neat since MFC’s are being investigated for cleaning waste water! Exciting to see a kid independently discover this use for MFCs. Wouldn’t it be interesting if one day your backyard septic tank powered a microbial fuel cell? Your household waste could be cleaned up AND produce power! Even better, big businesses such as agriculture and food and beverage processing could use this method to take their human waste to make microbial waste to then make human treasure – hehehe. The power of microbes – their poop and farts are our food and energy!
If you’re excited about the “treasures” that we humans get from microbial “trash”, check out the DoughLab also by Magical Microbes. You can purchase individual and classroom/outreach sized kits of the MudWatt and DoughLab together or separately from the Magical Microbes website.
Other related posts:
Microbial Trash is Human Treasure, Part I: Food – Fungal Farts and Bacterial Poop
GiantMicrobes: When Teachers Throw Things
Farty party and Brains On! excellent Farts podcast
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