Initialising the digital twin...
Initialising the digital twin...
Research project · Mawhiba · King Faisal University
Living bacteria
that make electricity
BioVolt is a microbial fuel cell where Geobacter bacteria eat organic waste and hand their electrons to an electrode. A digital twin and an AI supervisor read every signal, diagnose trouble within ten minutes and keep the colony alive and productive.
Wastewater carries 1.7 to 2.1 kWh of chemical energy in every cubic metre, yet treatment plants spend about 0.3 kWh/m³ just blowing air into it. In a microbial fuel cell the bacteria do the cleaning and pay for it in electrons. The catch: the colony is alive. A pH dip, a cold night or a toxic pulse can halve the output or kill the biofilm, and by the time a human notices, days of energy are gone. BioVolt watches the cell like a doctor, with physics it can explain.
charge locked in every gram of COD
Nernst ceiling of an acetate cell
model open-circuit voltage (0.798 measured)
biofilm doubling time (6 to 8 h in the lab)


Same cell, same shock
Ten simulated days, a severe acid shock at hour 72, identical bacteria. The only difference is who is in charge.
Before · passive
After · BioVolt AI
Figures from the Recovery Lab running on this site's live engine. Re-run them yourself.
Open the Recovery LabLive dashboard
This is not a recording. A simulated cell is running in your browser right now: electrons flow at the speed of the real current, the biofilm thickens as it grows and the chamber tints as pH drifts.
Faraday, Nernst, Butler-Volmer and Monod kinetics solved every minute of simulated time, then corrected against the sensors.
Eleven fault signatures scored in parallel. Every action comes with its cause, the physics behind it and a prediction you can check.
Microwatts, not kilowatts. Every figure on this site comes from the same engine you can open in the Calculation Lab.
The AI supervisor
Not a chatbot and not a black box. Every ten simulated minutes it compares what the cell does with what physics says it should do, names the most likely cause and acts. Faults caught inside 15 minutes recover fully; untreated acid shocks took 60 hours on average in the literature.
BioVolt AI supervisor
● Online · model confidence 100%
Try it: break the cell
Waiting for the next supervisory cycle…
The twin predicts voltage, pH and current from the inputs alone, then assimilates the sensors to learn the hidden biofilm state.
A CUSUM on the gap between sensor and twin flags drift long before a threshold alarm would.
Eleven physical signatures are scored at once. pH falling first means acid. Current falling with normal pH and temperature means something is killing cells.
Buffer, isolate, feed, heat or re-tune the load, each with its cause, a testable prediction and a confidence score.
How it works
01
Wastewater or blended food waste enters the sealed anode chamber. Dissolved sugars and acids are ready at once; solids must first be hydrolysed, which is why a one-day retention time unlocks only about 5% of them.
Xp → S (k_h · f_T · f_pH)02
Geobacter oxidises acetate and, with no oxygen around, breathes the electrode instead. Each acetate molecule releases eight electrons through conductive pili and cytochromes.
CH₃COO⁻ + 4H₂O → 2HCO₃⁻ + 9H⁺ + 8e⁻03
Electrons travel through the external load. Faraday's law sets the exchange rate: one gram of COD is worth 12,061 coulombs, so every microamp can be traced back to grams of waste removed.
Q = n·F·(ΔCOD/M) = 12,061 C/g04
Protons cross the membrane and meet oxygen and electrons at the cathode, making water. The cathode, not the bacteria, is usually the bottleneck: biofilms can deliver 3 to 7 A/m² while real cells draw 0.1 to 0.4.
O₂ + 4H⁺ + 4e⁻ → 2H₂O05
Every ten minutes the AI compares sensors with the twin, diagnoses, and adjusts the load, buffer, feed or heat. Once a day a lab COD sample recalibrates it.
P = V² / R_ext → R_ext* ≈ R_intThe project in pictures
The physical cell, the electronics that read it, the waste it eats and the scale it could reach.





The first photo is the team's prototype. The others are illustrations generated for this site.
Applications
Not the grid. The best 1000 L pilot recovered 0.033 kWh per cubic metre. The value is treatment with less energy, and power exactly where wires cannot reach.
Clean water without blowing air. Aeration is the biggest power bill of a treatment plant, and sludge yield drops about 4.7 times.
A 3.4 mW sediment cell ran a 2.5 W buoy in bursts by charging a capacitor. No batteries to replace at sea.
The biofilm is a living detector. A sudden current drop with normal pH and temperature means something toxic arrived.
PEE POWER stacked 432 cells to light festival toilets with about 300 mW, turning waste into safety lighting.
Reported power from solid food waste ranges from 1 to 371 mW/m², and up to 1540 when the waste is fermented first.
Electrochemistry, microbiology and control theory in one living system, with a twin that shows every hidden variable.
Questions
Your turn
Inject an acid shock, a toxin or a failing sensor, then watch the AI diagnose it in real time. Or open the lab and check every equation yourself.